In fiscal year 2011 , there were 100 U.S. Border Patrol agents in the various Border Sectors . Note : Numbers of unauthorized immigrants are at their lowest levels since 1990 . The figures can be tough to determine .
In fiscal year 2011 , there were 18,506 U.S. Border Patrol agents in the Southwest Border Sectors . Study : Apprehensions of unauthorized immigrants are at their lowest level since 1971 . The figures can be tough to interpret .