Please review my IELTS essay

Topic: The graph below shows the number of enquiries received by the Tourist Information Office in one city over a six-month period in 2011.

My essay:

The line graph illustrated how many requests were received by Tourist Information Office in a country during six months in the year 2011.

In general, it can be seen from the graph that there was two trend which is increasing and decreasing. Over the surveyed period, the number of questions which is sent by person or by mobile phone increased while that of figure sent by letter decreased. In addition, the amount of transmitting inquiry witnessed the most significant change in comparison to the other two methods.

The number of enquiries in person started at 400 in January which is the lowest figure among other. Then, it saw a sharply go up between February and June, from about 100 per month to 400 per month. With regard to telephone questions which had a highest beginning, about 880 in January and decreased to 800 in the next month. The amount of enquiries by phone remained stable in March to April and then jumped gradually to 1600 in June.

In contrast, the figure of inquiries by letter/mail felt slowly from 780 to 700 in January to March, respectively. In the next period, it dropped steadily to 380 and stayed constant in May to June.