The graph below shows the production levels of main fuels in a European country from 1981 to 2000

The line graph illustrates the amount of main fuels produced, namely petroleum, coal and natural gas in a European country between 1981 and 2000
Overall, the production levels of petroleum and natural gas increased over the period shown, while the amount of coal decreased
In 1981, around 100 tonnes of petroleum was produced, while there was only 40 tonnes of natural gas. The amount of natural gas has remained the same until 1994, then it halved to 80 tonnes in 2000. The production level of petroleum peaked at 130 tonnes in 1983, then leveled off in the next five years, and fluctuated thereafter. In 2000, it stood at 120 tonnes
Coal was generated about 80 tonnes in 1981, then it has remained stable until 1984. There was a brief dip 50 tonnes, followed by a slight rise. From 1987 to 2000, it gradually fell and reached its lowest point at approximately 40 tonnes