| | Northfield, IL | Mount Juliet, TN | United States |
| Population | 5,853 | 38,059 | 329,725,481 |
| Female Population | 54.8% | 49.6% | 50.5% |
| Male Population | 45.2% | 50.4% | 49.5% |
| Median Age | 49.5 | 38.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,458 | 24,988 | 309,327,143 |
| Population - 2000 | 5,389 | 12,366 | 285,036,114 |
| Population - 1990 | 4,635 | 5,389 | 251,960,433 |
| Pop. 2000 to Now | 0.0% | 211.6% | 15.6% |
| Pop. 1990 to Now | 16.2% | 614.9% | 30.8% |
| space4 | | | |
| Population Density | 1,812.1 | 1,534.5 | 93.4 |
| Land Area | 3.2 | 24.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Northfield, IL | Mount Juliet, TN | United States |
| Age 0 to 4 | 4.9% | 6.4% | 5.9% |
| Age 5 to 9 | 9.5% | 8.3% | 6.1% |
| Age 10 to 14 | 6.6% | 7.8% | 6.6% |
| Age 15 to 17 | 4.8% | 4.5% | 3.9% |
| Age 18 to 20 | 2.0% | 2.6% | 4.0% |
| Age 21 to 24 | 0.8% | 4.3% | 5.2% |
| Age 25 to 34 | 3.7% | 10.7% | 13.8% |
| Age 35 to 44 | 10.9% | 16.2% | 12.9% |
| Age 45 to 54 | 16.0% | 13.2% | 12.6% |
| Age 55 to 59 | 8.4% | 5.8% | 6.7% |
| Age 60 to 64 | 8.9% | 6.1% | 6.3% |
| Age 65 to 74 | 14.2% | 9.5% | 9.6% |
| Age 75 to 84 | 5.8% | 3.7% | 4.5% |
| Age 85 and over | 3.5% | 0.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Northfield, IL | Mount Juliet, TN | United States |
| White | 88.8% | 79.0% | 59.4% |
| Black | 0.2% | 7.0% | 12.2% |
| Asian | 3.6% | 3.9% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 1.8% | 0.4% |
| Two or More Races | 2.3% | 2.1% | 3.2% |
| Hispanic | 5.1% | 6.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Northfield, IL | Mount Juliet, TN | United States |
| Married Population | 65.5% | 60.9% | 49.8% |
| Currently Married | 65.3% | 60.3% | 48.0% |
| Married but Separated | 0.2% | 0.6% | 1.8% |
| Single Population | 34.5% | 39.1% | 50.2% |
| Never Married | 17.3% | 23.3% | 33.8% |
| Divorced | 8.7% | 11.3% | 10.8% |
| Widowed | 8.5% | 4.5% | 5.6% |
| space5 | | | |
| Household Size | 2.46 | 2.78 | 2.60 |
| Households | 2,383 | 13,672 | 124,010,992 |
| Family Households | 1,718 | 10,446 | 80,755,759 |
| Married couple, w/children | 33.4% | 40.2% | 30.5% |
| Married couple, no children | 51.8% | 41.9% | 42.9% |
| Non Family Households | 665 | 3,226 | 43,255,233 |
| Single householder, w/children | 12.0% | 13.9% | 15.8% |
| Single householder, no children | 2.9% | 4.0% | 10.8% |