The line chart illustrates the average amount of 
carbon
 Use synonyms
dioxide
 released by a person ( in metric Use synonyms
tonnes
) in 4 different European countries over the 40-year Use synonyms
peiod
 of Correct your spelling
period
time
. The X-axis shows the Use synonyms
time
 period from 1967 to 2007 Use synonyms
while
 the Y-axis gives data on the quantity of Linking Words
carbon
 Use synonyms
dioxide
 emitted.
 In the United Kingdom, the CO2 emission decreased gradually over the Use synonyms
time
 period Use synonyms
whereas
 in Portugal and Italy,Linking Words
a
 significant growth can be observed up until the year 1997 and after that emissions remained almost  at the same level in the following 10 years. 
In Remove the article
apply
sweden
, Change the capitalization
Sweden
Carbon
 Use synonyms
dioxide
 release showed an upward trend from 1967 to 1977 when it peaked, Use synonyms
then
 it declined continuously over the next 30 years. Linking Words
Linking Words
However
 out of all 4 countries, the UK was the largest CO2 emitter during the given Add a comma
,However
time
 range which was closer to 11  metric Use synonyms
tonnes
  Use synonyms
while
 Linking Words
the 
Portugal was the least contributor which was about 1 metric Correct article usage
apply
Use synonyms
tonnes
 in 1967.  In 2007, both Sweden and Portugal emitted an equal amount of Change to a singular noun
tonne
Carbon
 Use synonyms
dioxide
 which was around 5.5 metric Use synonyms
tonnes
.Use synonyms