All observation are July 1 estimates of each year.
This series is calculated by FRB-St. Louis using data series from the Census Bureau. The FRB-Cleveland District includes all of Ohio, western Pennsylvania, eastern Kentucky, and the northern section of West Virginia.
Source: US. Bureau of the Census
US. Bureau of the Census, Resident Population in FRB-Cleveland District [D4POP], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/D4POP, May 2, 2016.