About 11.2 million illegal immigrants were living in the United States in 2010, a number essentially unchanged from the previous year, according to a report published Tuesday by the Pew Hispanic Center, a nonpartisan research organization in Washington.

Despite continuing high unemployment among American workers, record deportations by the Obama administration and expanding efforts by states to crack down, the number of unauthorized immigrants in the work force  about eight million  was also unchanged, the Pew report found. Those workers were about 5 percent of the American work force.

The population of illegal immigrants leveled off after peaking in 2007 at 12 million, then dropping sharply over two years to 11.1 million in 2009, according to the report, which is based on census data. The declines occurred primarily because fewer people from Mexico and Central America came illegally to the United States, Pew concluded.

The report found no evidence of an exodus of illegal immigrants from the country. In particular there is no sign that Mexicans, who are the largest group  58 percent  of illegal immigrants, are leaving in larger numbers, the report finds.