| | Knoxville, IL | Tulsa, OK | United States |
| Population | 3,258 | 410,652 | 329,725,481 |
| Female Population | 54.8% | 51.2% | 50.5% |
| Male Population | 45.2% | 48.8% | 49.5% |
| Median Age | 42.2 | 35.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,910 | 392,289 | 309,327,143 |
| Population - 2000 | 3,183 | 393,049 | 285,036,114 |
| Population - 1990 | 3,243 | 367,302 | 251,960,433 |
| Pop. 2000 to Now | -15.4% | 2.6% | 15.6% |
| Pop. 1990 to Now | -17.0% | 9.8% | 30.8% |
| space4 | | | |
| Population Density | 1,386.4 | 2,079.1 | 93.4 |
| Land Area | 2.4 | 197.5 | 3,531,905.4 |
| Water Area | 0.0 | 4.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Knoxville, IL | Tulsa, OK | United States |
| Age 0 to 4 | 7.1% | 6.9% | 5.9% |
| Age 5 to 9 | 7.4% | 6.8% | 6.1% |
| Age 10 to 14 | 6.3% | 7.0% | 6.6% |
| Age 15 to 17 | 4.5% | 3.8% | 3.9% |
| Age 18 to 20 | 3.2% | 4.0% | 4.0% |
| Age 21 to 24 | 2.1% | 5.4% | 5.2% |
| Age 25 to 34 | 10.8% | 15.3% | 13.8% |
| Age 35 to 44 | 13.0% | 12.9% | 12.9% |
| Age 45 to 54 | 11.4% | 11.3% | 12.6% |
| Age 55 to 59 | 6.2% | 6.1% | 6.7% |
| Age 60 to 64 | 5.6% | 5.9% | 6.3% |
| Age 65 to 74 | 11.0% | 8.9% | 9.6% |
| Age 75 to 84 | 7.4% | 4.0% | 4.5% |
| Age 85 and over | 4.0% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Knoxville, IL | Tulsa, OK | United States |
| White | 94.1% | 53.2% | 59.4% |
| Black | 0.2% | 14.6% | 12.2% |
| Asian | 0.3% | 3.4% | 5.6% |
| Native American | 0.0% | 4.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 2.5% | 7.0% | 3.2% |
| Hispanic | 2.9% | 17.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Knoxville, IL | Tulsa, OK | United States |
| Married Population | 57.9% | 44.8% | 49.8% |
| Currently Married | 55.0% | 42.4% | 48.0% |
| Married but Separated | 2.9% | 2.4% | 1.8% |
| Single Population | 42.1% | 55.2% | 50.2% |
| Never Married | 24.7% | 35.0% | 33.8% |
| Divorced | 9.5% | 14.4% | 10.8% |
| Widowed | 7.9% | 5.7% | 5.6% |
| space5 | | | |
| Household Size | 2.58 | 2.41 | 2.60 |
| Households | 1,195 | 167,948 | 124,010,992 |
| Family Households | 824 | 95,296 | 80,755,759 |
| Married couple, w/children | 34.2% | 28.7% | 30.5% |
| Married couple, no children | 47.9% | 38.3% | 42.9% |
| Non Family Households | 371 | 72,652 | 43,255,233 |
| Single householder, w/children | 12.9% | 21.3% | 15.8% |
| Single householder, no children | 5.0% | 11.6% | 10.8% |