Methodology

1. Purpose, Scope & Platform Role

India does not have a single, centrally administered spot price for gold or silver. The domestic price at any given moment is an outcome of multiple interacting markets: the London over-the-counter market, the USD/INR currency market, the Multi Commodity Exchange of India (MCX), the India Bullion and Jewellers Association (IBJA), and the retail pricing decisions of individual jewellers. Each of these institutions produces a price, but each price represents a different stage of the supply chain — from international wholesale to domestic futures to consumer retail. Consumers, researchers, and market participants encounter different numbers depending on which source they consult.

This document describes how metalspread.com derives, converts, and presents the prices shown on this platform. It identifies the benchmark sources used, the conversion formulas applied, the assumptions embedded in those formulas, and the conditions under which displayed prices may diverge from actual transaction prices. The intent is to make every figure on this site reproducible and its limitations transparent.

metalspread.com is a market data reference platform. It is not a trading venue, a broker, or an exchange. It does not facilitate transactions, hold customer funds, execute orders, or provide personalised financial recommendations. The platform aggregates publicly available market data and presents derived prices for informational and research purposes. No price displayed on this site constitutes an offer, solicitation, or executable quote.

2. Editorial Responsibility & Review Policy

The methodology described in this document is maintained by the platform operator. Responsibility for the accuracy of price derivations, the selection of benchmark sources, and the calibration of assumptions rests with the platform's editorial function.

Review Schedule

This methodology is subject to a scheduled review at least once per quarter, or sooner if triggered by a material event. Events that may prompt an unscheduled review include:

• A change in customs duty rates, GST structure, or import policy announced through the Union Budget or government notification.
• A structural change to any referenced benchmark — for example, a modification to the LBMA auction process, a change in MCX contract specifications, or the discontinuation of a referenced data source.
• The introduction of a new domestic price discovery mechanism, such as a physical spot exchange, that materially alters the price-formation chain described in this document.
• Identification of a material error in the derivation logic or assumptions by internal review or external feedback.

Change Communication

All substantive changes to this methodology are recorded in the change history at the end of this document, with the date of change and a summary of what was modified. The effective date at the top of this page reflects the most recent revision. Typographic or formatting corrections that do not affect the substance of the methodology are not recorded.

Readers who rely on this methodology for research, reporting, or compliance purposes are encouraged to check this page periodically and to contact hello@metalspread.com with questions, corrections, or feedback.

3. The Three-Layer Price Structure

Gold and silver prices in India can be understood through three distinct layers. Each layer adds costs, risks, and market dynamics that cause prices to diverge from one another. Understanding which layer a given price belongs to is essential for interpreting any gold rate encountered in the market.

Layer 1 — International Benchmark

The London Bullion Market Association (LBMA) Gold Price, set through an electronic auction administered by ICE Benchmark Administration, is the primary global reference for gold. It is denominated in US dollars per troy ounce and published twice daily (10:30 AM and 3:00 PM London time). For silver, the LBMA Silver Price follows a similar auction process. These benchmarks represent the wholesale price for large-bar, London Good Delivery bullion traded between institutions in the London OTC market. They do not include import duties, currency conversion, or any costs specific to the Indian market.

Layer 2 — Domestic Wholesale

To arrive at an Indian wholesale price, the international benchmark must pass through currency conversion (USD to INR), customs duties (Basic Customs Duty and Integrated GST), and the cost-of-carry economics of the Indian futures market. The MCX near-month gold and silver futures contracts are the most actively traded precious metal instruments in India, and their last traded price reflects the market's consensus on the landed cost of bullion plus expected supply and demand conditions. The IBJA publishes a daily gold rate that is widely referenced by the domestic bullion trade and typically reflects MCX settlement prices from the prior session. This layer represents the price at which institutional participants — refineries, bullion dealers, and large jewellers — transact or hedge.

Layer 3 — Retail

National and regional jewellery retailers publish daily rates for 24-karat, 22-karat, and 18-karat gold. These retail prices include the wholesale bullion cost plus a margin that covers refining, fabrication, brand and distribution overheads, inventory financing, and Goods & Services Tax (GST at 3% on gold). This margin is commonly referred to as the jeweller premium and is distinct from making charges, which are applied per piece at the time of purchase. The retail layer is what a consumer encounters when buying gold from a jewellery store, and it is always higher than the domestic wholesale price.

4. Reference Benchmarks

metalspread.com references the following benchmarks and market prices, each of which plays a specific role in the Indian price-formation chain:

• LBMA Gold Price & Silver Price — Published by ICE Benchmark Administration following an electronic auction among accredited participants. The PM fix (3:00 PM London) is the more widely referenced settlement. Denominated in USD per troy ounce. This is the starting point for calculating the theoretical landed cost of gold in India.
• MCX Futures (Gold & Silver) — Near-month gold and silver futures traded on the Multi Commodity Exchange of India. Quoted in INR per 10 grams at 995 fineness (gold) and INR per kilogram (silver). Trading hours are Monday through Friday, 9:00 AM to 11:30 PM IST. MCX settlement prices serve as the primary domestic wholesale reference on this platform.
• IBJA Daily Rate — The India Bullion and Jewellers Association publishes a daily gold rate in INR per gram, typically mid-morning IST. This rate is widely used by jewellers and bullion dealers as a trade reference and generally tracks the previous MCX settlement adjusted for the opening market.
• USD/INR Exchange Rate — The prevailing exchange rate sourced from NSE currency derivatives. After the LBMA benchmark itself, the USD/INR rate is the largest driver of intraday gold price movement in INR terms.
• Gold ETFs — Exchange-traded funds listed on NSE and BSE that hold physical gold. Their market price, normalised to a per-10-gram basis using each fund's unit structure, provides an additional reference for the domestic gold price during equity market hours (Monday through Friday, 9:15 AM to 3:30 PM IST).
• Jeweller Published Rates — Daily retail prices for 24K, 22K, and 18K gold published by national and regional jewellery chains (including Tanishq, Malabar Gold, Kalyan Jewellers, and others). These rates are typically updated once every 24 hours and represent the price a consumer would encounter before making charges are applied.

5. The Economics of Futures-Based Price Discovery

India does not currently operate a centralised physical spot exchange for gold. The India International Bullion Exchange (IIBX) at GIFT City facilitates qualified imports but does not yet serve as a broad-based spot price discovery venue for the domestic market. In the absence of such a mechanism, the MCX near-month futures contract has emerged as the most significant reference for domestic gold pricing. This is not an arbitrary choice — it is a consequence of how price discovery works in commodity markets where spot trading is fragmented.

Why Futures Lead Spot in India

In textbook commodity markets, spot and futures prices are linked by the cost-of-carry relationship: the futures price equals the spot price plus the cost of storing and financing the commodity until the delivery date. In India's gold market, this relationship operates in reverse from a price-discovery perspective. Because there is no centralised spot market to anchor prices, the futures market — where thousands of participants continuously bid and offer — becomes the primary venue where information about supply, demand, and import economics is aggregated into a single price.

• Liquidity concentration — MCX gold and silver futures are among the most liquid commodity contracts in India, with participation from jewellers, refineries, bullion dealers, proprietary trading firms, and institutional hedgers. This broad participation means the futures price reflects a wide range of market intelligence about current and expected conditions.
• Continuous information incorporation — The futures price adjusts in real time to changes in the LBMA benchmark, USD/INR movements, shifts in import duty expectations, seasonal demand patterns, and global risk sentiment. Physical spot transactions, by contrast, occur bilaterally and are reported with a lag, if at all.
• Arbitrage linkage to international markets — If the MCX price diverges materially from the theoretical landed cost of imported gold, arbitrageurs can import physical bullion (or adjust hedging positions) to close the gap. This arbitrage mechanism keeps the MCX price tethered to international benchmarks while also reflecting India-specific factors.
• Downstream price setting — IBJA declares its daily gold rate after considering the MCX opening price, which means MCX price movements typically lead the official bullion association rate rather than follow it. Retail jewellers, in turn, reference the IBJA rate or the previous MCX settlement when setting their published prices for the following morning.

The MCX near-month futures price typically trades at a small premium to the theoretical landed cost. This premium — the basis or contango — reflects the cost of financing physical inventory to the delivery date and any localised supply-demand imbalance. In normal market conditions, this premium is modest (typically under 1%), but it can widen during periods of physical shortage, import disruption, or elevated demand.

For these reasons, metalspread.com uses the MCX near-month futures price as its domestic base price for gold and silver, rather than attempting to construct a theoretical landed cost from international inputs alone. The MCX price is a market- determined value that already incorporates the collective assessment of all the factors that a theoretical model would need to estimate individually.

6. Price Derivation

The following steps describe how prices displayed on metalspread.com are calculated. Formulas are presented in financial notation for reproducibility.

Step 1 — International Price per Gram

The LBMA PM Fix is converted from troy ounces to grams:

Price per gram (USD) = LBMA PM Fix (USD/oz) ÷ 31.1035

Step 2 — Currency Conversion

The USD gram price is converted to INR using the prevailing USD/INR exchange rate:

Price per gram (INR) = Price per gram (USD) × USD/INR rate

Step 3 — Theoretical Landed Cost Range

Importing gold into India incurs statutory duties and variable commercial costs. The statutory component consists of Basic Customs Duty (BCD) and Integrated GST (IGST) levied on the CIF value plus BCD. Beyond statutory duties, importers bear financing charges, insurance, freight, and refining costs that vary by consignment, route, and commercial arrangement.

The total cost of importing gold into India generally falls within the following range above the international benchmark:

The theoretical landed cost formula used for reference purposes on this platform applies only the statutory component:

Landed cost (INR) = Price per gram (INR) × (1 + BCD rate) × (1 + IGST rate)

This formula produces a floor estimate. The actual cost to any given importer will be higher by the variable commercial costs listed above. Duty rates are subject to change through government policy; the rates used here are reviewed as described in Section 2.

Step 4 — Domestic Base Price

Rather than relying solely on the theoretical landed cost, metalspread.com uses the MCX near-month futures last traded price as its domestic base. This price already reflects the market's collective assessment of landed cost, supply-demand dynamics, and cost of carry, as explained in Section 5. MCX quotes gold in INR per 10 grams at 995 fineness.

Step 5 — Purity Adjustment

MCX gold futures are standardised at 995 fineness. To derive prices for other purities, a proportional adjustment is applied:

Price per 10 g (purity) = MCX price per 10 g × (target fineness ÷ 995)

Standard target fineness values: 999 (24-karat), 916 (22-karat), 750 (18-karat).

Step 6 — Unit Conversion

Prices are presented in multiple units using the following conversion factors from the per-10-gram base:

• Per gram: base price ÷ 10
• Per troy ounce: base price × 3.11035 (i.e., 31.1035 g/oz ÷ 10)
• Per kilogram: base price × 100
• Per tola: base price × 1.166 (1 tola = 11.66 grams)

7. Assumptions & Parameters

The following assumptions are embedded in the price derivations above. Changes to any of these parameters — whether through policy action, market structure evolution, or updated data — will affect the accuracy of displayed prices until the parameter is revised through the review process described in Section 2.

8. Update Cadence & the Settlement-to-Retail Lag

Different benchmarks are published at different intervals, reflecting the structure of their respective markets. The following table summarises the expected update frequency for each price source referenced by this platform:

The Settlement-to-Retail Timing Lag

A structural timing lag exists between the wholesale settlement and the retail rate that consumers encounter. Understanding this lag is important for interpreting why the jeweller price on a given morning may not match the MCX price visible at that moment:

1. MCX closes at 11:30 PM IST. The official settlement price for the trading session is published shortly after close. This is the last wholesale price signal of the day.
2. Overnight, international markets continue to trade. Gold trades in London, New York, and Asian OTC markets while Indian exchanges are closed. By the time Indian markets reopen, the LBMA AM Fix and Asian trading may have moved the international price.
3. IBJA declares its daily rate mid-morning IST, typically after considering the MCX opening and any overnight international movement. This rate serves as the reference for the day's bullion trade.
4. Retail jewellers publish their daily rates in the morning, based on the previous evening's MCX settlement and/or the IBJA declaration. Most national chains update once; some may revise mid-day if intraday MCX movement exceeds a threshold.

This sequence means there is an inherent lag of approximately 10–18 hours between the MCX settlement that anchors a jeweller's rate and the moment a consumer sees that rate. On days of significant overnight movement in international markets or the USD/INR rate, the jeweller's published rate may already be stale by mid-morning. This lag is a structural feature of the market, not a data delay specific to this platform.

9. Price Classification: Indicative vs Executable

A formal distinction exists between indicative prices and executable quotes. This distinction is standard in financial market infrastructure and determines what reliance a reader may place on a published figure.

Indicative Price

An indicative price is a derived estimate published for informational purposes. It reflects market conditions at or near the time of publication but does not represent a commitment by any party to buy or sell at that level. Indicative prices may diverge from the price available in an actual transaction due to timing lag, bid-ask spreads, counterparty-specific terms, and transaction size. All prices published on metalspread.com are indicative.

Executable Quote

An executable quote is a firm price at which a counterparty commits to transact for a defined quantity, duration, and set of terms. Executable quotes are provided by brokers, dealers, and exchanges operating under regulatory authorisation. metalspread.com does not provide executable quotes and is not authorised to do so.

Classification of Displayed Prices

The following table classifies each price type displayed on this platform:

No price on this platform should be treated as a basis for contractual settlement, margin calculation, or regulatory reporting without independent verification against an authorised source.

10. Data Validation Procedures

Before any incoming data point is used in price derivation or displayed to users, it is subject to the following validation procedures. These checks are designed to prevent the propagation of erroneous, stale, or anomalous data through the derivation chain.

Range Validation

Each incoming price is checked against an expected range derived from the previous valid observation. If an incoming value deviates beyond the configured threshold, it is flagged for review rather than published immediately. The thresholds are calibrated to accommodate normal intraday volatility while catching data errors — for example, a misplaced decimal, an incorrect currency denomination, or a stale value replayed with a current timestamp.

Staleness Detection

Each data source has a defined maximum age beyond which the observation is considered stale. The age is measured from the source's own publication timestamp, not from the time of ingestion. When a data point exceeds its staleness threshold, the platform continues to display the last valid observation but indicates the data age to the user where applicable. The staleness thresholds are aligned with the expected update cadence of each source as described in Section 8.

Cross-Source Consistency

Where multiple sources provide overlapping price signals — for example, MCX gold futures and the LBMA-derived theoretical landed cost — the platform monitors the spread between them. A persistent or sudden divergence beyond the historically observed range may indicate an error in one of the input feeds. Such divergences are logged and reviewed; they do not automatically suppress publication but may trigger the error identification process described in Section 13.

Validation Failure Handling

When an incoming data point fails validation, the platform applies the following hierarchy:

1. Retain last valid observation. The most recent data point that passed all validation checks continues to be used in derivation and display.
2. Flag the data age. Where the retained observation exceeds the expected update interval, the platform indicates that the displayed value is based on the prior session or an earlier timestamp.
3. Suppress if irrecoverable. If no valid observation is available and the data age exceeds the maximum tolerable staleness for that source, the affected price or derived metric is withheld from display rather than published with an unreliable input.

11. Latency Classification

Each data source referenced by this platform operates with a characteristic latency — the time between a market event and the availability of the corresponding data point for display. The following classification defines the latency tiers used in this methodology and assigns each source to a tier.

The latency tier of each input directly affects the freshness of any derived price that depends on it. A derived price is only as current as its least-current input. For example, the jeweller premium percentage — derived from a near-real-time MCX base and a daily-observed jeweller rate — inherits the daily- observed latency of the jeweller input, regardless of how current the MCX component is.

12. Market State Handling

The prices displayed on this platform depend on multiple markets that operate on different schedules and are subject to interruptions. The following describes how the platform determines market state and how display behaviour adapts to each state.

Market States

State Determination

Market state is determined by the MCX trading calendar and scheduled session times. The platform does not independently determine whether an exchange is operational — it infers state from the presence or absence of incoming data within expected windows. If data ceases during a period when the exchange is expected to be open, the platform treats this as a potential disruption and engages the staleness and validation procedures described in Section 10.

Cross-Market State Divergence

Because different markets operate on different schedules, the platform frequently operates in a mixed state — for example, MCX may be open while NSE equity markets (and therefore ETF prices) are closed, or MCX may be closed while the LBMA PM auction publishes a new benchmark. In such cases, each data source independently follows its own state logic. Derived metrics that depend on multiple sources (e.g., the jeweller premium, which requires both an MCX base and a jeweller rate) inherit the most conservative state: if either input is stale, the derived metric is treated as stale.

13. Error Identification & Correction

Errors in published prices may arise from incorrect input data, derivation logic faults, parameter misconfiguration, or display formatting issues. The following procedures govern how errors are identified, classified, corrected, and communicated.

Error Categories

Detection

Errors are detected through three channels:

• Automated validation — Range checks, staleness detection, and cross-source consistency monitoring as described in Section 10.
• Internal review — Periodic manual review of displayed prices against independent references (e.g., comparing displayed MCX base against the MCX settlement published on the exchange website).
• External report — Users, researchers, or other external parties who identify a discrepancy and report it to hello@metalspread.com.

Correction Workflow

1. Classify the error by category and assess its impact — specifically, which displayed prices were affected, for how long, and by what magnitude.
2. Correct the source of the error. For input errors, ingest the corrected value from the source. For derivation or parameter errors, correct the logic or parameter and re-derive affected prices. For display errors, correct the rendering.
3. Verify the correction against an independent reference to confirm the corrected output is accurate.
4. Publish the corrected values. Corrected prices replace the erroneous values in the current display.

Restatement Policy

metalspread.com does not maintain a historical price archive for public consumption. Corrections are applied to the current display only. If a material error is identified that affected prices for an extended period, a note will be added to the methodology change history (Section 19) describing the nature, duration, and magnitude of the error. Users who relied on affected data during the error period and require further detail may contact the platform operator.

14. Operational Responsibility

The following table assigns responsibility for each operational function involved in producing and maintaining the prices displayed on this platform. All functions are performed by the platform operator unless otherwise noted.

The platform operator maintains a functional separation between engineering work (building and operating the derivation pipeline) and editorial work (defining methodology and reviewing output) to ensure that implementation decisions receive independent methodological review.

15. From Bullion to Retail: The Jeweller Premium

The price published by a jewellery retailer for 24-karat gold is typically higher than the corresponding MCX-derived bullion price. This difference — the jeweller premium — reflects the economic costs incurred between the wholesale bullion market and the retail display case:

• Refining and assay costs — converting imported bars or recycled gold into retail-grade bullion of certified fineness.
• Inventory carrying cost — jewellers hold physical stock and bear the financing cost of capital locked in unsold inventory, as well as insurance and storage.
• Brand and distribution overhead — retail space, staffing, marketing, and the fixed costs of operating a national or regional chain.
• GST (3%) — Goods & Services Tax on the sale of gold, collected at point of sale and remitted to the government.

metalspread.com calculates the jeweller premium as:

Premium (%) = (Jeweller 24K price − MCX-derived 24K base price) ÷ MCX-derived 24K base price × 100

This premium typically ranges from 2–3% for national chains and may be lower for online-first or digital-gold platforms with reduced overhead. It is important to note that the premium does not include making charges, which are a separate fee (typically 5–25% of metal value) applied on a per-piece basis at the time of purchase.

16. Regional Price Variation

Gold and silver prices are not uniform across Indian cities. Several structural factors contribute to observed regional variation:

• Logistics and transportation — India's primary bullion import hubs are Mumbai, Ahmedabad, and Chennai. Transporting gold from these hubs to inland cities adds 0.1–0.5% to the cost, depending on distance and security requirements.
• Regional demand patterns — Per-capita gold consumption varies significantly across states. Southern India historically exhibits higher demand, particularly during wedding and festival seasons, which can create localised price pressure.
• Repricing frequency — Dealers and jewellers in major metropolitan markets may adjust prices multiple times per day in response to MCX movements, while tier-2 and tier-3 city dealers may reprice only once daily. This lag can produce temporary divergence between cities.
• Competitive density — Cities with a larger number of competing jewellers and bullion dealers tend to exhibit tighter spreads, as competitive pressure compresses margins.
• Proximity to exchange vaults — MCX-accredited delivery vaults are concentrated in Mumbai and Ahmedabad. Physical delivery costs are lower for dealers near these locations, which can result in marginally lower wholesale prices in those cities.

17. Reading the Data: Consumer Interpretation Guidance

The prices displayed on metalspread.com serve different audiences — consumers comparing jeweller rates, researchers tracking price-formation dynamics, and market participants monitoring wholesale benchmarks. To avoid misinterpretation, the following clarifications describe what each displayed price represents and, equally important, what it does not.

The Headline Gold Price

The headline price shown on metalspread.com represents the domestic wholesale level, derived from the MCX near-month futures contract, adjusted for the selected purity. This is not the price at which a consumer can purchase physical gold from a retailer. It is the price at which institutional participants — refineries, large bullion dealers, and jewellers with MCX hedging operations — reference the market. A consumer buying gold jewellery will pay this price plus the jeweller premium plus making charges.

Jeweller Prices

Jeweller prices shown on this platform represent the published retail rate for bullion or coin before making charges. The total cost of a finished jewellery piece will be higher by the applicable making charge, which varies by design complexity, piece weight, and retailer. When comparing jewellers, the published rate indicates the base metal cost; the making charge must be enquired separately.

The Jeweller Premium Percentage

This metric measures the markup of a retailer's published 24K rate over the MCX-derived base. It is useful for comparing the relative pricing of different retailers on the same day. However, a lower premium does not necessarily indicate a lower total purchase cost — making charges, buyback policies, hallmarking standards, and certification practices also affect the total cost of ownership.

LBMA and International Prices

These are shown for reference and cross-market comparison. They represent the London wholesale market for Good Delivery bars and cannot be directly compared to Indian retail prices without accounting for duties, currency conversion, logistics, and the domestic supply-demand premium. A consumer should not expect to purchase gold in India at the LBMA price.

ETF Prices

ETF prices reflect the secondary market trading price of gold-backed exchange-traded funds on NSE or BSE. They may trade at a small premium or discount to their net asset value (NAV) depending on market liquidity and investor sentiment. ETF prices are relevant to investors in financial gold instruments but do not represent the cost of acquiring physical gold.

City-Specific Prices

City-specific prices are estimates based on the national wholesale base adjusted for known regional factors such as logistics, demand patterns, and competitive density. They represent the expected prevailing rate in that city, not a quote from any specific dealer. Actual transaction prices at a particular retailer may differ.

18. Sources of Uncertainty

Every price displayed on this platform is a derived estimate, not a direct market observation. Several structural features of the Indian gold market introduce uncertainty that no methodology can fully eliminate. Understanding these sources of uncertainty is part of using the data responsibly.

Temporal Uncertainty

Gold is traded across multiple time zones, but no single Indian market operates 24 hours. MCX closes at 11:30 PM IST; NSE currency derivatives close at 5:00 PM IST; equity markets close at 3:30 PM IST. Between these closing times and the next session's open, international gold prices, USD/INR rates, and global risk conditions may move materially. Any price displayed outside trading hours represents the last available data point, not the current market level. During periods of high volatility — geopolitical events, central bank announcements, or sharp currency moves — the gap between displayed and actual market prices can widen substantially.

Structural Spread Uncertainty

Physical bullion markets are bilateral and over-the-counter. The prices shown represent a mid or indicative level and do not reflect the bid-ask spread that a buyer or seller would face in an actual transaction. Spreads vary by dealer, transaction size, relationship, and market conditions. In periods of physical shortage or elevated demand, spreads can widen significantly, meaning the effective purchase price may be materially higher than the indicative price shown.

Policy Uncertainty

Customs duty rates, GST rates, and import regulations are instruments of government policy and can change through Union Budget announcements, GST Council decisions, or executive notifications. Such changes may take effect immediately or with short notice. Displayed prices use the duty and tax rates in effect at the time of the last methodology review (see Section 2) and may not immediately reflect policy changes. Significant changes will be incorporated through the review process, but a brief lag is inherent.

Currency Uncertainty

The USD/INR exchange rate is the second-largest driver of INR gold price movements after the international gold price itself. Currency markets are influenced by a broad range of macroeconomic, geopolitical, and monetary policy factors. The exchange rate used in price derivation is the most recently available rate, which may differ from the prevailing interbank rate at any given moment — particularly during periods of rapid currency movement or outside NSE currency market hours.

Model Simplification

The price derivation methodology described in this document uses a simplified model of the gold supply chain. It does not model individual importer economics, regional tax variations, recycled gold supply dynamics, or the impact of gold monetisation or sovereign gold bond schemes on domestic supply. These factors can, at times, cause market prices to diverge from model-predicted values.

Scope of Use

All prices on metalspread.com are published for informational and research purposes. They are not executable quotes, not a basis for contractual settlement, and not a substitute for independent professional advice. Consumers, investors, and market participants should verify prices through their broker, dealer, or jeweller before making transaction decisions.

19. Methodology Change History

Substantive changes to this methodology are recorded below. Typographic, formatting, or stylistic edits that do not affect the derivation logic or assumptions are not listed.

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