The four mainstays of the economy are agriculture, tourism, offshore financial services, and raising cattle. Vanuatu sells citizenship for about $150,000, and its passports allow visa-free travel throughout Europe. With demand from the Chinese market booming, passport sales may now account for more than 30% of the country's revenue. There is substantial fishing activity, although this industry does not bring in much foreign exchange. Exports include copra, kava, beef, cocoa and timber; and imports include machinery and equipment, foodstuffs, and fuels. In contrast, mining activity is very low.