Occupation and industry data are drawn from the United States Bureau of the Census. This is supplemented with data from the U.S. Federal Deposit Insurance Coporation (FDIC) for figures on commerical and savings bank offices and deposits, and from the American Medical Association for estimates on physicians.
TRAC compiled county level data into federal district units
and then calculated relevant percents, averages and
rankings to facilitate their comparison to other states,
federal districts, and counties in the country.