The given graph illustrates the production output of several kinds of energy resources in the United Kingdom between 1981 and 2000. Overall, there were fluctuations in petroleum refinement and coal mining, but there was mainly an upward trend for natural gas production.
For the 20-year span between 1981 and 2000, petroleum has been the highest produced fuel compared to natural gas and coal. It started at 90 energy units refined in 1981, but it reached its peak in 1999 at around 145 energy units. Although the petroleum production went down in 1991, it then started to trend upward.
Coal was the only fossil fuel that experienced a downward trend, starting at 80 energy units mined in 1981 and decreasing to below 40 energy units mined in 2000. On the other hand, natural gas production remained mainly flat from 1981 to 1991 at around 40 energy units before skyrocketing to 100 energy units in the following decade.
