"Burma?s mineral output was small by world standards but important to its domestic economy. Its most important mineral or mineral-related production was cement, copper, natural gas, nitrogen fertilizer, gem stones, lead, crude oil, silver, tin, and tungsten. By far the most valuable was oil and gas, its dollar value being several times the combined value of the other minerals. Burma was one of the few South or East Asian nations that has been self-sufficient in crude oil. That enviable position, however, was in danger of changing as energy needs have increased while crude oil production has at best shown no real gain in the last few years. As such, Burma has had an increasingly severe shortage of petroleum that has affected all segments of the economy. A firm policy of not importing oil, mainly because of a severe shortage of foreign exchange, was exacerbating the problem. The Government has set the highest priority on finding additional onshore crude oil reserves. Burma was a major producer of lead and silver before World War II and in 1986 was still considered to have good potential for developing or expanding the production of antimony, copper, lead, tin, tungsten, and zinc among the metals and barite, fluorite, and several other industrial minerals. About 74,000 persons were employed in state-owned mining activities and another 13,000 by the cooperative and private sectors. In all, 0.6% of the labor force was employed in the mining sector..."