"Of the Balkan states, Romania made the greatest advances. Food processing, with the emphasis on flour and sugar, was the major industry. At the beginning of the twentieth century the oil of the Ploești region began to be exploited. Nevertheless, the country remained predominantly agricultural. In 1914 only 1.5 percent of the national wealth was in industry; agricultural products accounted for 75.7 percent of the exports. Bulgaria, Serbia, and Greece, of course, retained their strongly agrarian structures."