| | Muscle Shoals, AL | Zionsville, IN | United States |
| Population | 15,969 | 30,258 | 329,725,481 |
| Female Population | 52.1% | 49.5% | 50.5% |
| Male Population | 48.0% | 50.5% | 49.5% |
| Median Age | 38 | 41.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 13,248 | 24,494 | 309,327,143 |
| Population - 2000 | 11,924 | 8,775 | 285,036,114 |
| Population - 1990 | 9,611 | 5,281 | 251,960,433 |
| Pop. 2000 to Now | 24.8% | 234.4% | 15.6% |
| Pop. 1990 to Now | 54.8% | 455.6% | 30.8% |
| space4 | | | |
| Population Density | 966.1 | 565.5 | 93.4 |
| Land Area | 16.5 | 53.5 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Muscle Shoals, AL | Zionsville, IN | United States |
| Age 0 to 4 | 6.5% | 5.4% | 5.9% |
| Age 5 to 9 | 6.4% | 8.4% | 6.1% |
| Age 10 to 14 | 6.2% | 7.8% | 6.6% |
| Age 15 to 17 | 3.6% | 5.4% | 3.9% |
| Age 18 to 20 | 2.5% | 2.5% | 4.0% |
| Age 21 to 24 | 5.0% | 3.7% | 5.2% |
| Age 25 to 34 | 13.6% | 7.6% | 13.8% |
| Age 35 to 44 | 13.8% | 14.6% | 12.9% |
| Age 45 to 54 | 11.3% | 17.9% | 12.6% |
| Age 55 to 59 | 4.5% | 7.4% | 6.7% |
| Age 60 to 64 | 8.3% | 6.1% | 6.3% |
| Age 65 to 74 | 9.9% | 7.6% | 9.6% |
| Age 75 to 84 | 6.6% | 3.8% | 4.5% |
| Age 85 and over | 1.9% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Muscle Shoals, AL | Zionsville, IN | United States |
| White | 81.2% | 89.6% | 59.4% |
| Black | 11.7% | 2.0% | 12.2% |
| Asian | 0.8% | 4.2% | 5.6% |
| Native American | 0.2% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 1.4% | 1.5% | 3.2% |
| Hispanic | 4.7% | 2.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Muscle Shoals, AL | Zionsville, IN | United States |
| Married Population | 51.2% | 71.6% | 49.8% |
| Currently Married | 49.8% | 70.9% | 48.0% |
| Married but Separated | 1.4% | 0.7% | 1.8% |
| Single Population | 48.8% | 28.4% | 50.2% |
| Never Married | 23.8% | 20.9% | 33.8% |
| Divorced | 17.1% | 4.5% | 10.8% |
| Widowed | 7.9% | 3.0% | 5.6% |
| space5 | | | |
| Household Size | 2.55 | 2.79 | 2.60 |
| Households | 6,201 | 10,835 | 124,010,992 |
| Family Households | 4,266 | 9,033 | 80,755,759 |
| Married couple, w/children | 30.5% | 43.0% | 30.5% |
| Married couple, no children | 43.4% | 48.3% | 42.9% |
| Non Family Households | 1,935 | 1,802 | 43,255,233 |
| Single householder, w/children | 14.8% | 5.2% | 15.8% |
| Single householder, no children | 11.3% | 3.4% | 10.8% |