The widespread use of children in cocoa production is controversial, not only for the concerns about child labor and exploitation, but also because up to 12,000 of the 200,000 children working in Côte d'Ivoire, the world's biggest producer of cocoa, may be victims of trafficking or slavery. Most attention on this subject has focused on West Africa, which collectively supplies 69 percent of the world's cocoa, and Côte d'Ivoire in particular, which supplies 35 percent of the world's cocoa. Thirty percent of children under age 15 in sub-Saharan Africa are child laborers, mostly in agricultural activities including cocoa farming. Major chocolate producers, such as Nestlé, buy cocoa at commodities exchanges where Ivorian cocoa is mixed with other cocoa.