The given line graph shows the production levels of three main types of fuel (petroleum, coal, and natural gas) in a particular European country, from 1981 to 2000.
Overall, it can be seen that petroleum was by far the most produced type of fuel, while the amount of natural gas being produced was increasing rapidly.
In 1981, the amount of petroleum being produced was around 100 tonnes. It increased steadily over the next few years to reach around 130 tonnes before dropping back to just under 100 tonnes in 1989. It then rose up again to around 130 tonnes in 1995, where it fluctuated slightly until the end of the period.
Coal was the second most produced fuel in 1981, at 80 tonnes. Coal production remained constant until it dropped suddenly down to around 50 tonnes in 1985. It rose back up to just over 70 tonnes in 1987 before slowly declining over the next 13 years to just under 40 tonnes. The production of natural gas remained unchanged at about 40 tonnes until around 1991 when it began to rise exponentially. 
The  
given
 line graph  
shows
 the production levels of three main types of fuel (petroleum, coal, and natural gas) in a particular European country, from 1981 to 2000. 
Overall
, it can be  
seen
 that petroleum was by far the most  
produced
 type of fuel, while the amount of natural gas being  
produced
 was increasing  
rapidly
.
In 1981, the amount of petroleum being  
produced
 was  
around
 100 tonnes. It increased  
steadily
 over the  
next
 few years to reach  
around
 130 tonnes  
before
 dropping back to  
just
 under 100 tonnes in 1989. It then rose up again to  
around
 130 tonnes in 1995, where it fluctuated  
slightly
 until the  
end
 of the period.
Coal was the second most  
produced
 fuel in 1981, at 80 tonnes. Coal production remained constant until it dropped  
suddenly
 down to  
around
 50 tonnes in 1985. It rose back up to  
just
 over 70 tonnes in 1987  
before
  slowly
 declining over the  
next
 13 years to  
just
 under 40 tonnes. The production of natural gas remained unchanged at about 40 tonnes until  
around
 1991 when it began to rise  
exponentially
.