The U.S. Department of Homeland Security has, through the Office of Immigration Statistics, issued its estimate of how many illegal immigrants are residing in the U.S. The report indicates that there are approximately 11.5 illegal immigrants residing in the U.S. during in January of 2011. The Report further estimates that more than half of these illegal immigrants entered the U.S. during the years of 1995 and 2004, and that since 2007, it is unlikely that the illegal U.S. population has significantly increased.
The Report indicates that since 2007, there is no real significant increase in the number of illegal immigrants due to the U.S. suffering from high unemployment and due to the economy in Mexico improving. The Report indicates that despite the greater levels of border enforcement, fewer apprehensions are taking place. The Report attributes the lower number of apprehensions at the U.S. border being due to lower demand for Mexican nationals to enter the U.S. for employment reasons.
The number of unauthorized immigrants in the U.S. has not always remained the same. In 1980, the number of illegal immigrants doubled from 2 million to 4 million in the U.S. This number jumped to over 8 million by the year of 2000. The numbers indicated above reflect an approximation of illegal immigrants, and not immigrants that have authorization to remain in the U.S.