the workforce is employed in some tourism-related work. Additionally, the islands frequently are a starting point for private yacht charters to the neighboring British Virgin Islands. Other sectors The manufacturing sector consists of mainly rum distilling. The agricultural sector is small, with most food being imported. International business and financial services are a small but growing component of the economy. Most energy is also generated from imported oil, leading to electricity costs four to five times higher than the U.S. mainland. The Virgin Islands were the highest oil consumers per capita in the world in 2007. The Virgin Islands Water and Power Authority also uses imported energy to operate its desalination facilities to provide fresh water. Government The CIA World Factbook lists the value of federal programs and grants — $241.4 million in 2013, 19.7% of the territory's total revenues — and that "the economy remains relatively diversified. Along with the tourist industry, it appears that rum exports, trade, and services will be major income sources in future years". Tax and trade The U.S. Virgin Islands are an independent customs territory from the mainland United States and operate largely as a free port. U.S. citizens thus do not have to clear customs when arriving in the U.S. Virgin Islands, but do when traveling to the mainland. Local residents are not subject to US federal income taxes on U.S. Virgin Islands source income; they pay taxes to the territory equal to what their federal taxes would be if they lived in a state. Transport and communications The Henry E. Rohlsen International Airport serves St. Croix and the Cyril E. King Airport serves St. Thomas and St. John. The U.S. Virgin Islands is the only U.S. jurisdiction that drives on the left. This was inherited from what was then-current practice on the islands at the time of the 1917 transfer of the territory to the United States from Denmark. However, because most cars in the territory are imported from the mainland United States, the cars in the territory are left-hand drive. However, not all U.S. vehicle regulations are in force, and there are vehicles on the road that cannot be sold in the mainland U.S. Additionally, headlights use the U.S. pattern which casts light to the right, tending to blind oncoming drivers. Traffic signals are located on the opposite side of the road than they are in the U.S. mainland, and many