That's federal prison data. People who go to federal prison aren't necessarily the same cross-section of the population who go to state prison. Anyway, those

That's federal prison data. People who go to federal prison aren't necessarily the same cross-section of the population who go to state prison. Anyway, those numbers are certainly much younger than the median age in the USA nationally, which is 39 years with over 65s being 15% of the population.