The line graph illustrates the proportion of resources, such as petroleum, coal and natural gas in a European country over a span of 19 years. In general, it is evident from the chart that the expenditure for petroleum experienced fluctuations in its total price, whereas those for natural gas rose gradually between 1981 and 2000.
In 1981, petroleum accounted for the highest percentage among the three resources, which began at nearly 100 tonnes, indicating its vital role in the country’s energy expenditure. In the next three years, this proportion increased marginally by about 40 tonnes, after which it stabilized at approximately 135 tonnes. Subsequently, petroleum had fluctuated, ultimately ending at 120 tonnes in 2000.
Conversely, there was little change in the percentages of both coal and natural gas over a 10-year period, beginning at 80 tonnes and 40 tonnes in 1981, respectively. However, while the figure for coal later saw a sharp decrease from 60 to nearly 40 tonnes in a decade, the amount of natural gas experienced a consistent upward trend, rising to 80 tonnes by the end of the period.