Most of the data on US immigration flows do not come from the Census Bureau; rather, data from the Immigration and Naturalization Service, on the number of legal migrants entering the country, and from the Office of Refugee Resettlement on the number of refugees entering the country is used. Between 1970 and 1980, the foreign-born population in the US grew by some 4.5 million persons or an astounding 46%. The foreign-born population in the US is concentrated in a few geographic areas; 3.6 million, or 1/4 of the foreign-born, live in California, and New York and Florida together have another 1/4 of the foreign-born population. The concentration of the foreign-born population is very pronounced in metropolitan areas. Mexico supplied the largest fraction of the foreign-born population in the 1980 census. Over 5 out of every 6 or 84% of the foreign-born persons who came to the US before 1950 were born in Europe or Canada. The shift from Europe as the main source of immigration was marked by a shift to Latin America and Asia as the principal sources of recent migrants to the US. The Census Bureau has made a number of projections using different scenarios for fertility, mortality, and immigration. The middle migration series, roughly consistent with current levels of legal immigration, shows that the population would grow to about 311 million by 2080 from a current level of 237 million.