This
 graph shows the Linking Words
production
 level of used Use synonyms
fuel
 in the UK Use synonyms
since
 1981 until 2000. It is clear from the graph that the most important and main Change preposition
from
fuel
 Use synonyms
in
 petroleum, Correct your spelling
is
while
 coal and natural gas are less used in Linking Words
this
 period.
Linking Words
According to
 what is shown, the petroleum Linking Words
fuel
 Use synonyms
increase
 in 1981 from Replace the word
increased
aapproximately
 90 Correct your spelling
approximately
a approximately
energy
 Use synonyms
units
 to 140 Use synonyms
energy
 Use synonyms
units
 , which Use synonyms
become
 Wrong verb form
became
in 
the peak in 1986. Change preposition
apply
While
Linking Words
,
 coal Remove the comma
apply
fuel
 Use synonyms
fall
 suddenly from 80 Wrong verb form
fell
energy
 Use synonyms
units
 to around 40 Use synonyms
energy
 Use synonyms
units
 in 1986. Use synonyms
Whereas
, natural gas Linking Words
remain
 stable since 1981, until 1991 natural gas Wrong verb form
remained
production
 increased from 40 Use synonyms
energy
 Use synonyms
units
 it reached a high level of Use synonyms
production
 in 2000.
Use synonyms
To sum up
, we could say that Linking Words
Use synonyms
production
 of petroleum Correct article usage
the production
fuel
 was always on the top, Use synonyms
in contrast
 Linking Words
of
 coal Change preposition
to
fuel
 Use synonyms
that 
dropped slowly all Correct pronoun usage
apply
this
 period of time. Linking Words
Also
, we can see that the UK Linking Words
start
 to use more Wrong verb form
has started
of 
natural Change preposition
apply
fas
 as Correct your spelling
gas
a 
Correct article usage
apply
fuel
.Use synonyms