Many of the changes that have taken place since the 1950s reflect government decisions and the role of international organisations. . In 1961, coal accounted for 80 per cent of the UK's energy supply. Following a prolonged miners' strike in 1984-85 over mine closures and job losses, coal production declined rapidly. It had become increasingly expensive to mine and alternative energy sources were becoming available, particularly oil and gas from the Middle East. . In 1974, the international organisation OPEC (Organisation of Petroleum Exporting Countries) quadrupled the price of oil on the world markets. Fortunately the UK had started to develop its money through taxation. own North Sea oil and gas, with the first oil being produced in 1975. Multi-national oil companies were involved in exploration and production with the UK government taking . In the early 1990s, the EU's 'Gas Burn' directive was repealed. Up until then, the directive had imposed restrictions on the use of gas. Once repealed, the gas industry was able to grow rapidly.