A three-year average unemployment rate is a measure of long-term structural unemployment. It is calculated by dividing the three-year sum of persons unemployed by the three-year sum of the civilian labor force. The map uses natural breaks in the distribution to organize the data into groups of common values. Appalachian three-year average unemployment rates range from 3.4% to 16.5%. The Appalachian average is 5.4%. The U.S. average is 4.8%. For a list of county data by state, see the downloadable Excel file.