| PEOPLE | Quincy | Auburn | United States |
| Population | 40,633 | 53,380 | 308,035,306 |
| Pop. Density | 2,554 | 919 | 87 |
| Pop. Change | -2.27% | 25.49% | 8.07% |
| Median Age | 39.4 | 23.8 | 37.3 |
| Households | 17,151 | 22,111 | 116,716,292 |
| Household Size | 2.25 | 2.21 | 2.58 |
| Male Population | 47.90% | 50.09% | 49.27% |
| Female Population | 52.10% | 49.91% | 50.96% |
| Married Population | 47.03% | 29.52% | 47.02% |
| Single Population | 52.97% | 70.48% | 52.98% |
| ESTIMATED TOTAL POPULATION BY AGE | | | |
| Age 0 to 4 | 6.61% | 4.95% | 6.56% |
| Age 5 to 9 | 6.27% | 4.88% | 6.61% |
| Age 10 to 14 | 5.58% | 4.78% | 6.71% |
| Age 15 to 17 | 3.80% | 2.85% | 4.21% |
| Age 18 to 20 | 3.03% | 9.85% | 2.95% |
| Age 21 to 24 | 7.16% | 28.16% | 7.01% |
| Age 25 to 34 | 12.70% | 13.38% | 13.33% |
| Age 35 to 44 | 11.23% | 9.71% | 13.33% |
| Age 45 to 49 | 13.60% | 8.24% | 14.61% |
| Age 50 to 54 | 13.60% | 8.24% | 14.61% |
| Age 55 to 59 | 11.69% | 6.34% | 11.84% |
| Age 60 to 64 | 11.69% | 6.34% | 11.84% |
| Age 65 to 74 | 7.91% | 3.64% | 7.05% |
| Age 75 to 84 | 6.60% | 2.17% | 4.24% |
| Age 85 and over | 3.81% | 1.04% | 1.78% |
| RACE | | | |
| White | 90.82% | 75.06% | 72.41% |
| Black | 5.41% | 16.55% | 12.61% |
| Asian | 0.91% | 5.29% | 4.75% |
| American Indian | 0.18% | 0.28% | 0.95% |
| Other | 2.68% | 2.82% | 9.28% |
| Hispanic | 2.99% | 0.80% | 16.35% |
| Non-Hispanic | 97.01% | 99.20% | 83.65% |
| FAMILY | | | |
| Married, w/children | 26.76% | 35.71% | 30.42% |
| Married, no children | 44.63% | 36.76% | 42.46% |
| Single, w/children | 17.88% | 13.56% | 14.39% |
| Single, no children | 10.73% | 13.98% | 12.73% |
| Divorced | 11.01% | 5.74% | 10.62% |
| Separated | 3.35% | 3.64% | 4.97% |
| Widowed | 10.14% | 2.48% | 6.14% |
| Now Married | 46.92% | 29.94% | 46.32% |
| Never Married | 28.58% | 58.19% | 31.95% |
