The line graph illusrates data about tha amounts of fuel in a European country between 1981 and 2000. The production levels measured in tonnes. Overall, it is clear that there were significant changes in the amounts of fuel by all three types througout the period shown. Natural gas experienced a upward trend, while there was a considerable decline in Coal and the levels of petroleum fluctuated wildly during the period.
Examining the levels that become important over time, the amount od natural gas started at just under 40 tonnes in 1981, a figure that then remained stable untill 1991, after which it improved dramatically at about 88 tonnes in the final year.
Turning to the factors that became less important, starting at 80 tonnes in 1981, the tonnage of coal leveled off by 1984, and it decreased sharply from 80 to around 50 tonnes in 1985. After a significant rise in 1987, the figure witnessed a consistent decline, reaching to roughly 38 tonnes in 2000.
A wild fluctuation was observed in the amounts of petroleum across 19-year span. It constitutes around 98 tonnes, a figure buttomed out at 94 tonnes in 1992, before reaching its peak approximately 133 tonnes. However, the amounts of petroleum went down to 120 tonnes in 2000.