Over the past 25 years, the rate of incarceration in the United States has increased dramatically. In 1972, the incarceration rate was approximately 100 people per 100,000 population. By 1996, more than 450 people per 100,000 were incarcerated. Much of this increase has occurred since the mid-1980s, when the introduction of sentencing reforms such as mandatory minimum sentences, determinate sentencing, and "truth in sentencing" led to increased penalties for specific crimes.