By the numbers: Immigration and naturalization January 28, 2013 -- Updated 2134 GMT (0534 HKT) There were 11.1 million undocumented immigrants in the United States in 2011 2.5 million undocumented immigrants had settled in California in 2011 41 state legislatures passed bills dealing with immigration issues in 2012 (CNN) -- A bipartisan group of senators on Monday presented a legislative plan for comprehensive immigration reform one day before President Barack Obama was to offer his ideas. Those efforts, and possibly more to come, signal the largest movement in years aimed at overhauling the nation's immigration system. 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 (ICE) 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. January 28, 2013 -- Updated 2156 GMT (0556 HKT) With President Barack Obama's re-election victory propelled by strong Latino support, Democrats and Republicans in Congress have a stronger interest in cultivating support from a group with growing political clout. January 28, 2013 -- Updated 1421 GMT (2221 HKT) From 2010: Complex and divisive, illegal immigration was one of the top issues of the 2010 midterm elections. January 28, 2013 -- Updated 1727 GMT (0127 HKT) Comprehensive immigration reform. January 25, 2013 -- Updated 2005 GMT (0405 HKT) Vivek Wadhwa and Christine Romans discuss the importance of immigration reform and how it could help solve the jobs crisis in the U.S.