Economy of Belgium increased unemployment, stemming from the worldwide banking crisis. For 50 years through World War II, French-speaking Wallonia was a technically advanced, industrial region, with its industry concentrated along the sillon industriel, while Dutch-speaking Flanders was predominantly agricultural with some industry, mainly processing agricultural products and textiles. This disparity began to fade during the interwar period. When Belgium emerged from World War II with its industrial infrastructure relatively undamaged thanks to the Galopin doctrine, the stage was set for a period of rapid development, particularly in Flanders. The postwar boom years, enhanced by the establishment of the European Union and NATO
Languages of Belgium enjoy official status. Article 4 does however divide the country into linguistic areas, which form the basis of the federal structure: "Belgium has four linguistic areas: The French-speaking area, the Dutch-speaking area, the bilingual area of Brussels Capital and the German-speaking area." Before the federal structure and the language legislation gradually introduced in the 20th century, French was generally the only language used by public authorities. For example, the Dutch version of the Constitution has enjoyed equal status to the original French one only since 1967, and the German version only since 1991. Of the inhabitants of Belgium, roughly 59%