Illegal immigration across the southwest border of the United States has been a hotly debated topic in recent years. Many people argue that illegal immigration is related to the U.S. unemployment rate: when the unemployment rate is up, there are more attempts to cross the border illegally. The URL attached contains data on the number of apprehensions on the southwest border and the U.S. unemployment rate. Included are both yearly data since 1981 and monthly data since 2000.

Using these data, make an argument, one way or the other, for whether apprehensions are related to the unemployment rate.