Final answer:
The exact percentage of state prison inmates released is not provided in the question. However, the U.S. correctional population has declined since its peak in 2007, indicating an ongoing release of inmates. Current statistics can be found in reports from the Bureau of Justice Statistics.
Step-by-step explanation:
According to a report published by USA Today, a specific percentage of all state prison inmates are released over a certain period. However, the question did not provide a precise figure from the report. By analyzing data from the Bureau of Justice Statistics and other sources, we can see that a significant number of inmates are released each year, as the overall correctional population has decreased from its peak in 2007.
This decrease indicates that releases are occurring, as part of efforts to reduce the U.S. incarceration rate, which is the highest in the world. To determine the exact percentage of inmates released, we would refer to the most current statistical reports available from official sources like the Bureau of Justice Statistics.