Method (v0.3)

• Every answer is a range: the median and the 10th–90th percentile of recorded prices, with the sample size, period and a confidence label.
• Confidence: high = 50+ records, medium = 15–49, low = 5–14. Below 5 records we do not publish a figure.
• Home sales: official transaction records only. Aggregates only: we never return individual addresses or personal data for home sales.
• Fuel: the latest pump price each public station reports, for the chosen fuel.
• Price library: once a day we take a snapshot of each live source and keep, for each area and item, the median, 10th–90th percentile and count. That is what the history endpoints show. Only aggregates are stored.
• France (DVF): only plain sales of exactly one house or apartment are counted; sales that bundle several homes or commercial premises are left out. DVF arrives with a delay of several months, so the period shown is the latest available.
• England & Wales: standard-price sales (category A) only; repossessions and transfers to companies are excluded.
• Ireland (Property Price Register): the register is collected once a day into our price library; answers are rolling 3 to 36 month windows by county or Dublin postal district, full-market-price sales only. New homes are usually recorded without VAT.
• Italy: prices in force at 08:00 on the extraction day, self-service unless asked otherwise; prices not updated in 30 days are left out.
• Singapore COE: median of the winning premium across bidding rounds from the Land Transport Authority's official results.
• Information, not a valuation or offer.

Sources and licences

• Precios de carburantes en las estaciones de servicio terrestres (Ministerio para la Transición Ecológica y el Reto Demográfico (Geoportal de hidrocarburos), via datos.gob.es, ES): Spanish public-sector information reuse terms (Ley 37/2007, RD 1495/2011): reuse allowed with the source and update date cited. Exact licence text to be confirmed.. Source: Ministerio para la Transición Ecológica y el Reto Demográfico – precios de carburantes (datos.gob.es). Posted pump prices, not individual receipts. Restricted-sale stations are excluded.
• Demandes de valeurs foncières (DVF), geo-dvf per-commune files (Direction générale des Finances publiques (DGFiP), files prepared by Etalab, FR): Licence Ouverte / Etalab 2.0, plus the DVF reuse conditions (no re-identification of people; raw data not to be indexed by search engines). Source: DGFiP, Demandes de valeurs foncières (DVF), via geo-dvf (Etalab), Licence Ouverte 2.0. We return aggregates only (median, range, count), never addresses or parcels. Alsace-Moselle and Mayotte are not covered by DVF.
• Prix des carburants en France – flux instantané v2 (Ministère de l'Économie via data.economie.gouv.fr, FR): Licence Ouverte / Etalab 2.0. Source: Ministère de l'Économie – prix des carburants (Licence Ouverte / Etalab 2.0). Pump prices are what every customer pays at that station at that moment; they are posted prices, not individual receipts.
• Price Paid Data (HM Land Registry, GB (England & Wales)): Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right. This data is licensed under the Open Government Licence v3.0. We return aggregates only (median, range, count), never individual addresses. Standard-price sales only (category A).
• Residential Property Price Register (Property Services Regulatory Authority (PSRA), Ireland, IE (Ireland)): Creative Commons Attribution 4.0 (PSRA open data; wording to be confirmed with the publisher). Source: Property Services Regulatory Authority (PSRA), Residential Property Price Register. Licensed under CC BY 4.0. Aggregates only, by county or Dublin postal district and rolling window; never individual addresses. Excludes sales flagged 'not full market price' and records above EUR 10 million (bulk sales). New homes are usually recorded without VAT.
• Carburanti – Prezzi praticati e anagrafica degli impianti (Ministero delle Imprese e del Made in Italy (MIMIT), Osservaprezzi carburanti, IT): Italian Open Data Licence v2.0 (IODL 2.0). Fonte: Ministero delle Imprese e del Made in Italy – Osservaprezzi carburanti (IODL 2.0). Posted pump prices, not individual receipts. Prices not updated in 30 days are left out.
• COE bidding results and prices (Land Transport Authority via data.gov.sg, SG): Singapore Open Data Licence v1.0. Contains information from COE Bidding Results and Prices accessed from data.gov.sg, made available under the terms of the Singapore Open Data Licence version 1.0. The COE is the legal right to own a car in Singapore for 10 years, not the car itself. One premium per bidding round and category; all successful bidders pay the same premium.
• Resale flat prices (from Jan 2017) (Housing & Development Board via data.gov.sg, SG): Singapore Open Data Licence v1.0. Contains information from Resale flat prices accessed from data.gov.sg, made available under the terms of the Singapore Open Data Licence version 1.0. Public housing (HDB) only; private condominium sales are a separate source (not yet included).