Griffith, Bryan, and Steven Camarota. "County map: Growth of adult immigrant population, 1990 to 2014. Immigrant share of adults quadrupled in 232 counties." Center for Immigration Studies, September 2016.
The web page shows data on the United States’ adult illegal and legal immigrant populations at the county level.
As far as North Carolina was concerned, it stated that in Mecklenburg, Durham and Duplin counties, among others, the immigrant share of adults more than quadrupled from 1990 to 2014.
The data for the study came from the 1990 Census, the 2000 Census and the 2010 to 2014 five-year file of the American Community Survey.
Robeson County had one of the highest increases in immigrant share of adult population in the time period. In 1990, the share was only .60 percent, compared to 2014 when it had jumped all the way up to 6.7 percent out, of the total population of 134,913 people. That adds up to be a 973 percent increase in just 24 years.