The number of Americans in state prison or on parole or probation has fallen to the lowest level in a decade, while the number of people in federal prison has fallen for the first time in more than 30 years, the Washington Post's Reid Wilson reports. "The total incarceration rate has fallen ... from about one in every 100 adults to one in every 110 adults," Wilson further reports. However, the number of people incarcerated in the United States remains close to historic levels: "more than 1.5 million inmates are housed in state or federal prisons, and another 731,000 reside in local jails."