Britain oversaw foreign relations and defense for the ruling Kuwaiti Al-Sabah dynasty from 1899 until independence in 1961. Kuwait has the world's fifth largest proven oil reserves and is the fourth richest country in the world per capita. Kuwait is a small, rich, relatively open economy with self-reported crude oil reserves of about 96 billion barrels - 10% of world reserves. Petroleum accounts for nearly half of GDP, 95% of export revenues, and 80% of government income. Kuwait's climate limits agricultural development. Consequently, with the exception of fish, it depends almost wholly on food imports. About 75% of potable water must be distilled or imported. Kuwait continues its discussions with foreign oil companies to develop fields in the northern part of the country. High oil prices in recent years have helped build Kuwait's budget and trade surpluses and foreign reserves. As a result of this positive fiscal situation, the need for economic reforms is less urgent and the government has not earnestly pushed through new initiatives.