The given line graph illustrates the levels of production of three different types of fuels in the UK from 1981 and 2000.
In general, there was an increasing trend in producing petroleum and natural gas, whereas coal production went downwards throughout the period. Also, petroleum was produced the most amongst the three.
Looking at the figures for petroleum and natural gas, more than 90 energy units of the former and just 40 energy units of the latter were produced in 1981. Such an amount of natural gas then grew gradually, reaching almost 100 energy units in 2000. Petroleum, however, rose to 140 energy units produced in 1984 before dropping to just 100 energy units six years later. Until the end of the period, its figure increased steadily and returned to 140 energy units produced.
Turning to coal, its production level stood at around 60 energy units in 1986 after declining to just under 40 energy units two years ago. Afterwards, however, the figure went down gradually, reaching rock bottom at approximately 30 energy units in 2000.