The graph below shows the number of enquiries received by the Tourist Information Office in one city over a six-month period in 2011. Summarize the information by selecting and reporting the main features and make comparisons where relevant.

The line chart illustrated the figure of enquiries received by the Tourist Information Office in one city over a half-year period in 2011. Overall, it can be clearly seen that although the number of letter and email decreased over time, the rest was uptrend. In January, the total enquiries in person and by telephone stood approximately at 400 and 900, respectively. Three months later, the figure of person type enquiries overcame the telephone type by roughly 200, which stabilized at 1200 in April. Consequently, both categories of enquiries continued their momentum, which finally reached 1900 for the personal enquiries and 1600 for the telephone. In the meantime, letter and email enquiries declined marginally from 800 to 700 within the first two months of the period. Subsequently, there was a sharp drop by 300 in the next two months. After a down trend period, the figure levelled off roughly at 400 for a month.