| |
| Age Group | Male | Female | Cook County, Illinois, 2000, Universe: 001 Total population Universe Population: 5,376,741 | ||
| Population | Pct | Population | Pct |  | |
| Total | 2,603,532 | 48.4 | 2,773,209 | 51.6 | |
| 0- 4 | 198,013 | 3.7 | 190,188 | 3.5 | |
| 5- 9 | 207,703 | 3.9 | 198,805 | 3.7 | |
| 10-14 | 193,934 | 3.6 | 186,655 | 3.5 | |
| 15-19 | 188,831 | 3.5 | 179,344 | 3.3 | |
| 20-24 | 192,950 | 3.6 | 192,371 | 3.6 | |
| 25-29 | 222,291 | 4.1 | 222,074 | 4.1 | |
| 30-34 | 215,342 | 4.0 | 213,117 | 4.0 | |
| 35-39 | 210,144 | 3.9 | 212,788 | 4.0 | |
| 40-44 | 200,178 | 3.7 | 209,737 | 3.9 | |
| 45-49 | 173,419 | 3.2 | 186,522 | 3.5 | |
| 50-54 | 148,948 | 2.8 | 164,401 | 3.1 | |
| 55-59 | 112,214 | 2.1 | 128,287 | 2.4 | |
| 60-64 | 90,692 | 1.7 | 107,528 | 2.0 | |
| 65-69 | 75,299 | 1.4 | 94,064 | 1.7 | |
| 70-74 | 67,335 | 1.3 | 91,930 | 1.7 | |
| 75-79 | 53,015 | 1.0 | 81,092 | 1.5 | |
| 80-84 | 31,917 | 0.6 | 59,093 | 1.1 | |
| 85+ | 21,307 | 0.4 | 55,213 | 1.0 | |