Belgium's traditional industries face a number of challenges. Historically, the main industries were concentrated in the French-speaking areas of Wallonia. However, since the 1970s, the principal areas of industrial growth have been in Flanders. Newer light industries and more sophisticated technologies have replaced the older and labor-intensive manufacturing systems. Between Antwerp and Brussels, a new corridor of industries emerged. The majority of these were less labor-intensive and required more skilled workers. The principal industries that have fueled this growth have been the petro-chemical and refining sectors. Nonetheless, the remaining industries tend to be highly advanced and technologically sophisticated. Light manufacturing and refining increasingly dominate the industrial sector. The entire industrial sector accounted for 26 percent of GDP in 2000.