The line graph illustrates how many tonnes of three different fuels were produced in a European nation between 1981 and 2000. Overall, while the level of petroleum and natural gas witnessed an upward trend, a reverse pattern was documented for coal. Moreover, petroleum was the most produced fuel source throughout the years.
In terms of petroleum and natural gas, the former started the period at nearly 100 tonnes before it increased slightly to about 130 tonnes in 1983 and remained stable at this level for four years. Despite a sharp decline to approximately 90 tonnes in 1991, it rebounded to 120 tonnes by the end, maintaining the leading category. Meanwhile, there were 40 tonnes of natural gas manufactured annually from 1981 to 1994, after which the production level underwent a two-fold growth by the final year, surpassing that of the coal.
On the other hand, 80 tonnes of coal were generated in 1981, followed by a plateau until 1984. Subsequently, a moderate fall of around 30 tonnes was recorded in the level of coal produced in 1985 prior to a recovery to roughly 75 tonnes three years later. However, at the end of the timeframe, it dropped again to only 40 tonnes, registering the lowest number.