The line graph compares a European country in terms of their contribution to the production levels of main fuels between 1981 and 2000. Overall, petroleum and natural gas increased the production levels, albeit to varying degrees, with the exception of coal. Of particular note is that petroleum took the dominance in 2000. Units are measured in tonnes.
To start with natural gas, which remained intact at 40 tonnes from 1981 to 1991, and this figure for natural gas fluctuated mildly between 40 and about 42 tonnes from 1991 to 1994. However, the production levels of natural gas went up slowly to approximately 50 tonnes between 1994 and 1997 before increasing quickly to roughly 82 tonnes at the end of the period. In contrast, petroleum climbed gradually close to 130 tonnes from 1981 to 1983 prior to remaining static at about 130 tonnes between 1983 and 1987. Moreover, the production levels of petroleum declined noticeably to nearly 98 tonnes in 1989, and this number felled from 98 to about 90 tonnes between 1989 and 1991 before climbing dramatically from nearly 90 to 130. And the figure for petroleum oscillated mildly between about 130 and 133 tonnes prior to dropping considerably from nearly 134 to 120 tonnes between 1998 and 2000.
Conversely, the number of production levels of coal remained stable at 80 from the beginning of the period to 1984 before reducing significantly by approximately 47 tonnes. However, this figure again increased speedily to 78 tonnes before dropping slightly by 60 from 1987 to 1991. In addition to this, the incidence of the production levels of coal continued diving slowly from 60 to about 38 tonnes between 1991 and 2000.