Ariel's castle

This table shows a runner’s five-mile time in the first seven years. From the data it may be seen that the runner achieve the greatest decrease in the amount of time it takes to run five miles. At the end of the year, the runner takes about 45 minutes to run five miles. However, and at the end of the second year, the runner takes about 34 minutes to run five miles. There was a steady decrease during the following six years. During the seventh year, the runner takes about 31 minutes to run five miles. During the first seven year period, the amount of time decrease about 15.5 minutes.