The Yearbook comprises four chapters. The first covers demographic and social indicators, reflecting special efforts to mainstream the gender perspective in statistical information. The second chapter presents economic statistics relating to trade, balance-of-payments and prices, as well as national accounts. The third chapter provides the quantitative information available on the environment. Given the abundance of different, sometimes conflicting, data now accessible to researchers through the Internet, special attention must be paid to the data sheets on which the source of the data, their definition and coverage are specified. This information is presented in the fourth chapter, supplementing the more specific information contained in the footnotes to each of the tables of this Yearbook.