Could you please review my IELTS Task 1?

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Topic: I have attached the image of the question. Please review my IELTS Task 1 essay.

I would highly appreciate you for taking your precious time to identify and correct my mistakes, suggesting some improvements. Thank you.

My essay:

The graph presents how many enquiries in person, by letter and by telephone were received by the Tourist Information Office in a city over a half-year period in 2011 and breaks down the results by months.

Overall, enquiries in person quadrupled, with over-the-telephone enquiries nearly doubling over the period of six months. However, written enquiry levels dwindled to half of their initial number.

The amount of in-person enquiries increased sharply from over 400 to about 1900. Reducing from 900 to 800, in the first month, the number of telephone queries doubled, from 800 to 1600 in the following five months, without changing between March and April.

Despite the rise of the former pair of trends, however, it is also shown that the seeking of information by the letter or email subsided from approximately 750 to almost 400 over the first five months, remaining stable from May to June.