Data Source: This graph is an updated version of one that appeared in Tracking State Prison Growth in 50 States. The raw numbers were updated through 2015 in Data update: Incarcerated population inching down with the sources listed at the bottom of that post. The total population figures necessary to calculate the incarceration rates are described in the methodology section of Tracking State Prison Growth in 50 States, with recent years added from the U.S. Census Bureau's population estimates. (Graph: Joshua Aiken and Peter Wagner, 2017)