The line graph illustrates how three kinds of fuel in the UK were produced from 1981 to 2000.
Overall, there was a decline in coal while others experienced an upward trend. In addition, petroleum production witnessed the most significant units throughout the period.
From 1981 to 1991, the number energy units of petroleum producing around 90 units to 140 units then leveled off, after which being seen a decrease to 100 units while there was no change in natural gas production remained at 40 units in these years. By contrast, the data of coal witnessed very dramatically, started at double units in comparison with natural gas and hit the lowest to half units respectively and then went up gradually to nearly 45 units in 1991.
In 1991 onwards, the production levels of petroleum and natural gas climbed up steadily to 140 units and 100 respectively. followed by a slight decline of the coal form 45 units to about 39 units, Moreover, despite the second highest unit at the beginning, coal production have the lowest units in the ends