Ghana's economy is predominantly agricultural, which accounts for 35% of GDP and employs 60% of the work force. Gold, timber and cocoa productions, and individual remittances, are major sources of foreign exchange. Rice, coffee, cassava, peanuts, corn, shea nuts, and bananas are major crops. The mining industry in Ghana is the key sector in the economy with the principle minerals produced being gold and industrial diamonds, bauxite, and manganese. The oil industry is a key sub-sector of Ghana. The major industries in Ghana are mining, lumbering, light manufacturing, aluminum smelting, cocoa and other food processing, and shipbuilding. Ghana's major trading partners include neighbouring Nigeria, Germany, Switzerland, France, the Netherlands, United Kingdom, China, Japan and the United States.