The graph provides data on the manufacture 
levels
 of certain fuels, Use synonyms
such
 as Linking Words
petroleum
, natural Use synonyms
gas
 and coal in the UK from 1981 to 2000. The energy units are measured in numbers. One energy unit refers to one million tonnes of oil. 
Use synonyms
Overall
 the graph shows increases and decreases in Linking Words
production
 Use synonyms
levels
. Use synonyms
Petroleum
 and Coal increase and decrease in entirely separate directions, whole natural Use synonyms
gas
 shows no signs of growth. 
in 1981 Use synonyms
petroleum
 had an increase in Use synonyms
production
 Use synonyms
levels
, the graph shows a decrease until 1991, it wasn't until 1992 that Use synonyms
petroleum
 went back to Use synonyms
it's
 original growth. Replace the word
its
On the other hand
, natural Linking Words
gas
 had a slow Use synonyms
production
 rate  but started to increase steadily in 1998. Use synonyms
However
, Coal had a large drop in Linking Words
production
 rates and remained lower than its original measured Use synonyms
production
 level. Coal and natural Use synonyms
gas
 remain less popular than Use synonyms
petroleum
. Making Use synonyms
petroleum
 Use synonyms
production
 Use synonyms
levels
 a preferred option.Use synonyms