crime rose

Paper instructions:
From 1980 to 1990 crime rose at an alarming rate.  From 1990 through 2005, the rate fell significantly.  However, the number of individuals incarcerated consistently rose throughout the entire

period from 1973 through 2008.  In 1973, 96 people per 100,000 were incarcerated while by 2008 that number had climbed to 500 per 100,000.  How do you explain why the number of individuals

under correctional control does not reflect the rate of crime?