The estimated number of unauthorized immigrants peaked at 12.2 million in 2007 and fell to 11.3 million in 2009, breaking a rising trend that had held for decades. Although there are indications the number of unauthorized immigrants may be rising, the 2012 population estimate is the midpoint of a wide range of possible values and in a statistical sense is no different from the 2009 estimate.
Source: Pew Research Hispanic Trends Project, Population Decline of Unauthorized Immigrants Stalls, May Have Reversed by Jeffrey S. Passel, D’Vera Cohn and Ana Gonzalez-Barrera, September 23, 2013.