During the past decade, drug consumption surveys and expert analyses have warned about growing drug use in Latin America. According to the 2013 World Drug Report, cocaine use in Latin America increased significantly during the first decade of the 2000s while the U.S. cocaine market, although still the largest in the world, has been declining. Similar upward trends exist in marijuana, synthetic, and prescription drug use. These trends are seen as unprecedented as they affect primary drug producers, such as Colombia and Mexico, and are seen as generating significant violence.