| | Greenback, TN | Altamonte Springs, FL | United States |
| Population | 1,435 | 45,732 | 329,725,481 |
| Female Population | 47.2% | 55.1% | 50.5% |
| Male Population | 52.8% | 45.0% | 49.5% |
| Median Age | 30.6 | 36.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,100 | 41,573 | 309,327,143 |
| Population - 2000 | 954 | 41,200 | 285,036,114 |
| Population - 1990 | 611 | 34,879 | 251,960,433 |
| Pop. 2000 to Now | 29.8% | 6.3% | 15.6% |
| Pop. 1990 to Now | 102.6% | 25.6% | 30.8% |
| space4 | | | |
| Population Density | 172.7 | 5,031.6 | 93.4 |
| Land Area | 8.3 | 9.1 | 3,531,905.4 |
| Water Area | 0.1 | 0.6 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Greenback, TN | Altamonte Springs, FL | United States |
| Age 0 to 4 | 9.2% | 4.5% | 5.9% |
| Age 5 to 9 | 7.3% | 5.9% | 6.1% |
| Age 10 to 14 | 4.7% | 5.8% | 6.6% |
| Age 15 to 17 | 5.7% | 2.9% | 3.9% |
| Age 18 to 20 | 5.4% | 2.7% | 4.0% |
| Age 21 to 24 | 7.2% | 5.4% | 5.2% |
| Age 25 to 34 | 15.8% | 19.9% | 13.8% |
| Age 35 to 44 | 4.9% | 16.9% | 12.9% |
| Age 45 to 54 | 16.8% | 10.3% | 12.6% |
| Age 55 to 59 | 5.2% | 6.7% | 6.7% |
| Age 60 to 64 | 4.9% | 4.5% | 6.3% |
| Age 65 to 74 | 7.2% | 7.8% | 9.6% |
| Age 75 to 84 | 3.8% | 5.4% | 4.5% |
| Age 85 and over | 1.8% | 1.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Greenback, TN | Altamonte Springs, FL | United States |
| White | 97.6% | 46.6% | 59.4% |
| Black | 0.0% | 16.6% | 12.2% |
| Asian | 0.0% | 2.5% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.3% | 0.2% |
| Other | 0.6% | 1.1% | 0.4% |
| Two or More Races | 0.0% | 3.8% | 3.2% |
| Hispanic | 1.9% | 29.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Greenback, TN | Altamonte Springs, FL | United States |
| Married Population | 48.0% | 41.8% | 49.8% |
| Currently Married | 47.8% | 40.1% | 48.0% |
| Married but Separated | 0.2% | 1.8% | 1.8% |
| Single Population | 52.0% | 58.2% | 50.2% |
| Never Married | 38.4% | 36.6% | 33.8% |
| Divorced | 9.2% | 16.3% | 10.8% |
| Widowed | 4.4% | 5.2% | 5.6% |
| space5 | | | |
| Household Size | 3.72 | 2.19 | 2.60 |
| Households | 386 | 20,797 | 124,010,992 |
| Family Households | 318 | 10,663 | 80,755,759 |
| Married couple, w/children | 35.5% | 24.2% | 30.5% |
| Married couple, no children | 44.0% | 39.3% | 42.9% |
| Non Family Households | 68 | 10,134 | 43,255,233 |
| Single householder, w/children | 12.0% | 21.4% | 15.8% |
| Single householder, no children | 8.5% | 15.1% | 10.8% |