The graph illustrates the difference in the 
amount
 and type of junk food received by teenagers in Australia during the period from 1975 to 2000
In general, the Use synonyms
consumption
 of hamburgers and pizzas  per year increased during the 25 years , but Use synonyms
a
 number of fish and chips experienced a decrease during the same period.
After the Correct article usage
the
consumption
 of Hamburgers increased rapidly from 1975 to 1985, there was a steady rise in the Use synonyms
amount
 of Use synonyms
consumption
 between 1985 and 2000. There was a fluctuation in the Use synonyms
consumption
 of fish and chips during the period from 1975 to 1985. Use synonyms
Firstly
, the Linking Words
amount
 of Use synonyms
consumption
 of fish and chips decreased from 1975 to 1980, Use synonyms
then
 increased from 1980 to 1985. Linking Words
After 
Linking Words
this
 fluctuation, there was a drop between 1985 and 2000. The Linking Words
amount
 of Use synonyms
consumption
 pizza witnessed an increase from 1975 to 1995, reached the pick Use synonyms
at
 1995 and stayed Change preposition
in
constantfor
 5years.  In comparison, hamburgers had a  huge change in Correct your spelling
constant for
constant
consumption
.Use synonyms