In every year, the rates of first incarceration varied by age (figure 1). In 2001 sharply higher first incarceration rates were found for each older birth cohort up to a peak of 350 per 100,000 at age 20. These rates then dropped steadily with each older age category. [Illustration: Figure 1: First incarceration rates] ---------------------------------------------------------------------- Figure 1 +First incarceration rates rose sharply among persons under age 45+ Number first incarcerated per 100,000 U.S. residents.* Age at first incarceration 1974 1986 1991 2001 12 0 0 0 0 13 0 0 1 0 14 1 0 6 0 15 6 8 27 12 16 25 29 67 58 17 66 81 139 152 18 107 143 219 254 19 142 203 295 325 20 140 217 307 350 21 143 209 306 344 22 133 188 274 329 23 132 172 285 304 24 113 164 261 285 25 92 153 254 280 26 81 142 227 274 27 79 128 224 282 28 79 116 210 262 29 68 116 189 268 30 55 112 179 244 31 45 107 164 243 32 40 93 148 217 33 38 87 123 206 34 36 82 120 196 35 38 78 125 198 36 36 74 126 195 37 34 68 114 177 38 28 64 103 153 39 23 56 92 129 40 21 50 83 123 41 18 43 75 116 42 18 38 63 122 43 16 42 56 114 44 15 41 48 98 45 13 41 46 77 46 12 34 44 65 47 12 33 45 58 48 11 35 46 53 49 10 28 44 43 50 10 26 35 42 51 8 15 27 42 52 9 16 25 41 53 7 12 27 36