( 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 : . 11.5 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 . 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 . 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 . State legislation related to immigration . 2005 : 300 bills introduced ; 39 laws enacted ; 6 vetoed . 2006 : 570 bills introduced ; 72 laws enacted ; 6 vetoed ; and 12 resolutions adopted . 2007 : 1,562 bills introduced ; 178 laws enacted ; 12 vetoed ; and 50 resolutions adopted . 2008 : 1,305 bills introduced ; 139 laws enacted ; 3 vetoed ; and 64 resolutions adopted . 2009 : More than 1,500 bills introduced ; 202 laws enacted ; 20 vetoed ; and 131 resolutions adopted . 2010 : More than 1,400 bills introduced ; 208 laws enacted ; 10 vetoed ; and 138 resolutions adopted . 2011 : 1,607 bills introduced ; 197 laws enacted ; 15 vetoed ; and 109 resolutions adopted . 2012 : 948 bills introduced ; 111 laws enacted ; 2 vetoed ; and 92 resolutions adopted ( as of June 30 , 2012 )
There were 11.5 million undocumented immigrants in the United States in 2011 . The U.S. government has been cracking down on illegal immigration for years, but it's not clear how effective that crackdown is. It takes about five months on average to process an application for naturalization .