The line graph compares the manufacturing level of 3 primary kinds of fuel in the UK from 1981 to 2000.
Overall, while the production of petroleum and natural gas witnessed an upward shift, that of coal took the opposite direction. Among the three, petroleum had the highest production throughout the entire period.
In 1981, petroleum emerged as the dominant category, with around 90 energy units produced. This was followed by coal, at 80 energy units, double the figure for natural gas.
Thereafter, the level of petroleum production fluctuated with an upward trend, ending the period with 140 million units and still ranking first. Meanwhile, natural gas production saw a slight increase in the initial decade before surging to 100 energy units, overtaking coal as the second most prevalent fuel. Conversely, the trend for coal was generally downward, as its figure hit a low of approximately 35 energy units in 2000.