Here's a look at immigration and naturalization, by the numbers:

11.1 million: Estimated number of undocumented immigrants in the United States, as of 2011, the most recent year available as reported by the Pew Hispanic Center.

1.91 million: Estimated number of resident non-immigrant population as of January 2011. This number includes students, temporary workers, and diplomats and their families.

14: Percentage of the resident non-immigrant population that lives in California.

2.55 million: Estimated number of undocumented immigrants that settled in California as of February 2011, the most recent figures available.

482,300: Immigrant visas issued by the U.S. State Department in Fiscal Year 2012.

8: U.S. senators behind the bipartisan immigration reform plan: Democrats Chuck Schumer of New York, Dick Durbin of Illinois, Robert Menendez of New Jersey, and Michael Bennet of Colorado; and Republicans John McCain of Arizona, Lindsey Graham of South Carolina, Marco Rubio of Florida, and Jeff Flake of Arizona.

1.06 million: People who obtained legal permanent resident status in fiscal year 2011.

65: Percentage of those gaining LPR status that had a family relationship with a U.S. citizen or someone who already has legal, permanent status.

23.1: Millions of foreign-born workers in the U.S. labor force, as of 2010.

114: Bills enacted by 41 state legislatures in the first half of 2012 that addressed legal immigrants, migrants, and seasonal workers.

56,384: People admitted to the United States as refugees in 2011.

409,849: Individuals removed by the Immigration and Customs Enforcement in Fiscal Year 2012.

55: Percentage of those removed who were convicted criminals.

327,000: Immigrants apprehended by Customs and Border Patrol in Fiscal Year 2011.

20: States that require the use of "E-verify," which allows businesses to determine whether potential employees have the right to live and work in the U.S. as of November 2012.

2,955: Migrants intercepted by the U.S. Coast Guard in fiscal year 2012.

5 months: Length of time it takes for U.S. Citizenship and Immigration Services to process an application for naturalization.

100: Civics questions on the naturalization test.