The file Audits contains the number of audits of corporations with assets of more than $250 million

Question:

The file Audits contains the number of audits of corporations with assets of more than $250 million conducted by the Internal Revenue Service (data extracted from K. McCoy, "IRS Audits Big Firms Less Often," USA Today, April 15, 2010, p. 1B).
a. Construct a time-series plot.
b. What pattern, if any, is present in the data?