Rwanda's developing economy suffered heavily in the wake of the 1994 genocide, but has since strengthened. The economy is based mostly on subsistence agriculture. Coffee and tea are the major cash crops for export. Tourism is a fast-growing sector and is now the country's leading foreign exchange earner. Rwanda is one of only two countries in which mountain gorillas can be visited safely, and visitors pay high prices for gorilla tracking permits. Music and dance are an integral part of Rwandan culture, particularly drums and the highly choreographed ''intore'' dance. Traditional arts and crafts are produced throughout the country, including ''imigongo'', a unique cow dung art.