Source: U. S. Census Bureau, American Community Survey, 5-Year Estimates. Updated every year. http://factfinder2.census.gov
Foreign-born persons include anyone who was not a U.S. citizen at birth. This includes respondents who indicated they were a U.S. citizen by naturalization or not a U.S. citizen. Persons born abroad of American parents or born in Puerto Rico or other U.S. Island Areas are not considered foreign born.
Other survey questions determined the country of birth, year of entry, and citizenship status for the foreign born.
The percentage shown is obtained by dividing the count of foreign-born persons by the total population.
Scope and Methodology:
These data are collected in the American Community Survey (ACS). The data are estimates and are subject to sampling variability. The data for each geographic area are presented together with margins of error at factfinder2.census.gov. The data are period estimates, that is, they represent the characteristics of the population over a specific 60-month data collection period.