| PEOPLE | Fitchburg | Chicago | United States |
| Population | 25,260 | 2,695,598 | 308,035,306 |
| Pop. Density | 722 | 11,842 | 87 |
| Pop. Change | 20.20% | -7.16% | 8.07% |
| Median Age | 33 | 33.1 | 37.3 |
| Households | 9,955 | 1,045,560 | 116,716,292 |
| Household Size | 2.46 | 2.52 | 2.58 |
| Male Population | 51.63% | 48.53% | 49.27% |
| Female Population | 48.37% | 51.47% | 50.96% |
| Married Population | 48.72% | 31.20% | 47.02% |
| Single Population | 51.28% | 68.80% | 52.98% |
| ESTIMATED TOTAL POPULATION BY AGE | | | |
| Age 0 to 4 | 8.03% | 6.90% | 6.56% |
| Age 5 to 9 | 6.74% | 6.16% | 6.61% |
| Age 10 to 14 | 5.93% | 6.10% | 6.71% |
| Age 15 to 17 | 3.78% | 3.90% | 4.21% |
| Age 18 to 20 | 2.00% | 2.88% | 2.95% |
| Age 21 to 24 | 7.50% | 8.27% | 7.01% |
| Age 25 to 34 | 19.54% | 19.13% | 13.33% |
| Age 35 to 44 | 13.54% | 14.03% | 13.33% |
| Age 45 to 49 | 13.73% | 12.57% | 14.61% |
| Age 50 to 54 | 13.73% | 12.57% | 14.61% |
| Age 55 to 59 | 11.56% | 9.75% | 11.84% |
| Age 60 to 64 | 11.56% | 9.75% | 11.84% |
| Age 65 to 74 | 4.64% | 5.61% | 7.05% |
| Age 75 to 84 | 2.21% | 3.33% | 4.24% |
| Age 85 and over | 0.78% | 1.37% | 1.78% |
| RACE | | | |
| White | 72.17% | 44.99% | 72.41% |
| Black | 10.42% | 32.93% | 12.61% |
| Asian | 4.88% | 5.46% | 4.75% |
| American Indian | 0.41% | 0.49% | 0.95% |
| Other | 12.12% | 16.12% | 9.28% |
| Hispanic | 2.40% | 4.19% | 16.35% |
| Non-Hispanic | 97.60% | 95.81% | 83.65% |
| FAMILY | | | |
| Married, w/children | 34.92% | 26.11% | 30.42% |
| Married, no children | 40.70% | 31.85% | 42.46% |
| Single, w/children | 15.89% | 19.49% | 14.39% |
| Single, no children | 8.50% | 22.55% | 12.73% |
| Divorced | 8.93% | 9.22% | 10.62% |
| Separated | 2.68% | 7.36% | 4.97% |
| Widowed | 2.36% | 6.21% | 6.14% |
| Now Married | 49.28% | 31.70% | 46.32% |
| Never Married | 36.74% | 45.52% | 31.95% |
