Prior to 1996, the ISIC Rev. 3 classification system was used.
Product classification follows a numeration scale.
Mining and quarrying, manufacturing, electricity, gas and water supply. Entire area of the country. The prices collected refer to the 15th day of the reference month or as close to this date as possible. Important exceptions include refined petroleum products and crude petroleum, for which the prices are the averages during the reference month. The prices collected are net transactions prices received by the producers for their largest consignments.