The number of adult males under correctional supervision increased by 70% from 1986 to 1997 (2.8 million in 1986 to 4.8 million in 1997), with an overall average annual increase of 4.9% over the 11 year period. From 1986 to 1990, the average annual increase in the number of males under correctional supervision was 7.3%, with the smallest percentage increase occurring in 1988 (6.7%, or 202,000) and the largest percentage increase in 1989 (8.6% or 278,600). The average annual increase in the male population slowed to 3.6% from 1990 to 1997, with the largest percentage increase in 1991 (4.4%, or 166,700) and the smallest percentage increase in 1996 (2.6% or 117,100).
The number of adult females under correctional supervision increased by 118% from 1986 to 1997 (410,000 in 1986 to 895,000 in 1997), with an average annual increase of 7.4% over the 11 year period. From 1986 to 1990, the average annual increase in the number of females under correctional supervision was 10.0%, but there were large variations in the percentage increase recorded in individual years, ranging from 12.8% in 1989 (an increase of 62,900) and 12.0% in 1988 (an increase of 52,500), to 8.6% in 1990 (an increase of 47,700) and 6.9% in 1987 (an increase of 28,300). From 1990 to 1997, the average annual increase slowed to 5.8%, but this period was also marked by wide variations in the percentage increase in the female correctional population. The largest percentage increase in the female correctional population during this period occurred in 1992 (14.4%, an increase of 89,700). Otherwise, the largest percentage increase in the female population during this period was 7.6% in 1995 (an increase of 58,200), and the smallest percentage increase was 2.2% in 1993 (an increase of 15,900).