Given is a graph that presents average 
carbon
       Use synonyms
dioxide
 (CO2) emissions per head in four Use synonyms
countries
      from 1967 and 2007.            Use synonyms
Overall
, the United Kingdom and Sweden were Linking Words
educed
 the highest number of Correct your spelling
reduced
carbon
 Use synonyms
dioxide
 per head. Use synonyms
The both
 Remove the article
Both
countries
 decrease, and it continues to decline.       The other two Use synonyms
countries
 continue to increase.            Use synonyms
According to
 the graph below, Linking Words
United
 Kingdom is the      highest among the four Correct article usage
the United
countries
 Use synonyms
by
 the emission of Change preposition
in
carbon
       Use synonyms
dioxide
, Use synonyms
is 
nearly 11 metric Unnecessary verb
apply
tonnes
 and since       1977, it slowly Use synonyms
decreases
. Sweden Wrong verb form
decreased
increases
 until 1977      which Wrong verb form
increased
reaches
 Wrong verb form
reached
to 
above ten metric Change preposition
apply
tonnes
, but Use synonyms
then
 it Linking Words
declines
. Wrong verb form
declined
On the other hand
, Portugal and Italy are increasing during the period from 1967 to 2007.      Italy is almost four metric Linking Words
tonnes
 per person and       Portugal is approximately one metric tonne. By Use synonyms
the       
2007, both Change the article
apply
countries
 Use synonyms
are
 achieved Verb problem
had
to 
nearly eight and       6.5 metric Change preposition
apply
tonnes
. Use synonyms
However
, Linking Words
Italy
 increased Change noun form
Italy's
the 
emission of CO2 is not higher than the United Correct article usage
apply
Kingdom       
, which Change noun form
Kingdom's
is
 almost 8.3 metric Wrong verb form
was
tonnes
 in 2007. Sweden       the value of Use synonyms
carbon
 Use synonyms
dioxide
 emissionUse synonyms
 since       declined
 is the same level as Portugal in 2007Add the comma(s)
, since       declined,