The graph illustrates the changes in the production levels of three main fuels in a European country over a period of 19 years from 1981 to 2000.
Overall, it is apparent that there was an upward trend in the production of natural gas throughout the years while those of petroleum and coal experienced fluctuations. However, petroleum maintained the leading position in terms of production volume over the period shown.
In 1981, petroleum had the highest amount, with nearly 100 tonnes of petroleum being generated. After increasing and flattening out at 130 tonnes, its production level dropped significantly by 40 tonnes in 1991 and recovered to 120 tonnes in 2000. Meanwhile, coal ranked in the second place in 1981, at 80 tonnes. Its level of production remained unchanged until 1984 when it underwent a sudden decline to 50 tonnes. Despite recovering in the following years, it then decreased gradually to 40 tonnes in 2000, which was only a third of petroleum’s production amount in the same year.
In 1981, the production level of natural gas started at 40 tonnes, which was equal to that of coal in the year 2000. After undergoing a stable period of 13 years, it grew remarkably, surpassing that of coal in 1997 and ending at merely over 80 tonnes by the end of the period.