 According to the nonpartisan Pew Research Center, the number rose rapidly in the 1990s, "from an estimated 3.5 million in 1990 to a peak of 12.2 million in 2007," then dropped sharply during the Great Recession before stabilizing in 2009.Pew estimated the total population to be 11.1 million in 2014, or approximately 3 percent of the U.S. population.This "is in the same ballpark" as figures from the United States Department of Homeland Security (DHS), which estimated that 11.4 million undocumented immigrants lived in the United States in January 2012.