The economy is based largely on agriculture, which, including fisheries, provides 50% of the GDP and employees two-thirds of the work force, mostly in subsistence farming of food crops. In addition to agricultural exports, tourist revenues and remittances from overseas workers are also important sources of foreign exchange. Economic performance has suffered since 1990 due to the devastation to crops, tourism, and infrastructure caused by cyclones Ofa and Val. In 1993/94 a fungal disease reduced taro production by 97%, threatening the island's basic food crop and causing negative growth in the economy. Samoa has the highest unemployment rate and the lowest wages in Oceania.