Band 8+: The line graph below shows the number of complaints received by the complaints department of a single airline over a six-month period in 2009. Summarise the information by selecting and reporting the main features making comparisons where relevant.

The line graph illustrates the number of complaints made to an airline by customers through three different channels over a six-month period.

Overall, the number of in-person complaints rose sharply and became the most common method, while complaints by email or fax declined steadily. Telephone complaints increased moderately.

In January 2009, the number of telephone complaints was just over 900, making it the highest figure among the three methods at the start. Meanwhile, in-person complaints stood at around 400, the lowest figure. However, the number of in-person complaints rose dramatically throughout the period, overtaking the other two methods and peaking at over 1,800 in June.

Telephone complaints experienced a slight fall in February, but then began to increase steadily, nearly catching up with in-person complaints.However, it did not surpass it, ending at about 1,600 in June. By contrast, complaints sent by email or fax declined steadily, falling from around 800 in January to 300 in May, after which the figure remained stable.