The line graph illustrates the total tally of enquiries that have 
done
 by the tourist information office Add a missing verb
been done
in 
Change preposition
apply
a 
method of inviting in person and by letter or email or telephone in a particular city from January to June Correct article usage
apply
especially
 in 2011.
During January, the highest number of enquiries had been done by telephone and Add the comma(s)
,especially
then
 it started falling and rising till march, after that it remained relatively stable for Linking Words
Linking Words
next
 Correct article usage
the next
one 
month, Correct pronoun usage
apply
finally
 it has shown Linking Words
drastic
 improvement from after April to June.
The enquiries in person were the least in January approximately 400, and Correct article usage
a drastic
then
 it started steadily rising to almost Linking Words
by 
the triple Change preposition
apply
count
 Use synonyms
at the end
 of the period. The decent Linking Words
count
 was recorded by letter or email, Use synonyms
initially
, it started with an acceptable Linking Words
count
 and Use synonyms
then
 it was marginally falling till March and dramatically fell from approximately 700 to 400 between March to April and it showed similar results after April.
Linking Words
Overall
, Linking Words
although
 Linking Words
initially
 enquiring in person Linking Words
was 
seemed to be having the lowest Unnecessary verb
apply
count
 Use synonyms
but 
eventually, it outnumbered Remove the conjunction
apply
than 
others, which was as opposed to the enquiry by telephone Change preposition
apply
count
.Use synonyms