The provided graph illustrates information about the types of fuels that was produced in the United Kingdom from 1981 to 2000.
Overall, it can be seen that despite some fluctuations, the trend was downward. The category that saw the largest decline was coal, which decreased by almost eighty million tonnes.
Looking specifically at coal, which experienced the most unstable pattern, it is noticeable that it started the period as the highest produced fuel with approximately 120 million tonnes, then in 1983 it suffered from a major drop causing it to decline to almost 50, going forward, it started to increase reaching about 100 million, after that it kept on decreasing, reaching almost 40 million.
Regarding petroleum, it is safe to say that this category had the most stable and consistent pattern among all the observed categories, ranging from 100 to 80 million unites, without any sharp or sudden changes. On the other hand, regarding natural gas, almost 80 bcm of this category was produced in 1981, it showed an upward trend until 1991, reaching almost about 110 bcm, then it kept receding and reached just below eight bcm.
