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

The given line graph demonstrates how enquiries were received by the Tourist Information Office in a particular city via three different means in the first six months of 2011.

Overall, it is easily noticed that while the number of enquiries received in person and by telephone steadily increased, that for enquiries received by letter or email witnessed a constant decline. In addition to that, the quantity of enquiries conducted in person underwent the most significant change throughout the survey.

The figure for enquiries received via telephone slight dropped to 800 in February before experiencing a rebound to 1000 in March. At the same time, there was a gradual rise by approximately 400 in the number of enquiries received in person. Conversely, the quantity of enquiries via letter or email incrementally decreased from roughly 800 in January to 650 in March, losing its second position in rank to that for direct enquiries.

According to the chart, the period from March to April 2011 registered notable changes in the ranks of these three categories. After leaping from 800 to above 1200 in only one month, the figure for enquiries received in person dethroned that for via telephone, followed by a stable climb at a swift pace. The number of phone calls for enquiries shared the same trend as it went unchanged between March and April before resuming its increase to 1600 in June. In contrast, this period continued to see a diminution in the figure for enquiries received through letters and emails, ending up below the 400 mark at the end of the time covered.