Australia is the world's leading coal exporter. Uranium mining Uranium mining in Australia began in the early 20th century in South Australia. At 2016 Australia contained 29% of the world's defined uranium resources. The three largest uranium mines in the country are Olympic Dam, Ranger Uranium Mine and Beverley Uranium Mine. Future production is expected from Honeymoon Uranium Mine and the planned Four Mile Uranium Mine. Natural gas Based on 2008 CSIRO report, Australia estimated to have stranded gas reserves with about 140 trillion cubic feet or enough to fulfil the needs of a city with one million people for 2,800 years. Entrepreneurs and magnates At various stages in the history of the mining industry in Australia, individual mining managers, directors and investors have gained significant wealth and the subsequent publicity. In most cases the individuals are designated Mining Magnates or Australian mining entrepreneurs. Economics A number of large multinational mining companies including BHP, Newcrest, Rio Tinto, Alcoa, Chalco, Shenhua, Alcan and Xstrata operate in Australia. There are also many small mining and mineral exploration companies listed on the Australian Securities Exchange (ASX). Overall, the resources sector represents almost 20% of the ASX market by capitalisation, and almost one third of the companies listed. Mining is Australia’s largest sector by share of national Gross Domestic Product, 10.4% in 2020. This is up from only 2.6% in 1950, and from 10% at the time of federation in 1901. In 2020 mineral exports contributed 62% of Australia's total export revenue, valued at $270 billion. Australia is the world's largest exporter of coal (35% of international trade), iron ore, lead, diamonds, rutile, zinc and zirconium, second largest of gold and uranium, and third largest of aluminium. Japan was the major purchaser of Australian mineral exports in the mid-1990s. Of the developed countries, perhaps only Canada and Norway have mining as such a significant part of the economy; for comparison, in Canada mining represents about 3.6% of the Canadian economy and 32% of exports, and in Norway mining, dominated by petroleum, represents about 19% of GDP and 46% of exports. By comparison, in the United States mining represents only about 1.6% of GDP. The mining sector employed in 2021 about 270,000 people, about 2.0% of the total labour force. Australia’s mining industry is 86% foreign owned, Although many people think BHP and Rio Tinto as Australian companies, BHP is 76% foreign owned, and Rio