The line chart demonstrates the production levels of three different fuels in Britain from 1981 to 2000, comprising petroleum, coal and natural gas.
Overall, the amount of petroleum used for production was higher than that of the two remaining fuels, whereas that of coal ranked last in the last year of the 19-year period. Additionally, the figure for natural gas experienced an upward trend throughout the period.
During 19 years, since 1981, the production level of petroleum was the highest of the three main kinds of fuel in the UK. However, this figure experienced a changing trend over the same period. In particular, it went up from below 100 energy units in 1981 to approximately 140 energy units in 1984 before reaching a plateau at the same figure during the next 4 years. In addition, despite witnessing a downward trend from 1987 to 1990 (by precisely 40 energy units), the figure finally increased from 100 energy units from 1990 to reach the peak of over 140 energy units, just before its slight decrease in the last year of the overall 19-year period (140 energy units).
Turning to the two remaining figures for coal and natural gas, although the figure for the latter remained unchanged from 1981 to 1990 (with around 40 energy units), it finally grew before reaching 100 energy units and finally ranked second in 2000 (after petroleum). By contrast, with a decreasing trend during 19 years as well as its surprisingly reaching the bottom of below 40 energy units to rank third (after natural gas) in 1984, that of the former finally ranked last (with around 30 energy units in 2000).