| | Shell Rock, IA | Mulberry, FL | United States |
| Population | 1,616 | 3,920 | 329,725,481 |
| Female Population | 52.7% | 53.9% | 50.5% |
| Male Population | 47.3% | 46.1% | 49.5% |
| Median Age | 34.3 | 48.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,295 | 3,747 | 309,327,143 |
| Population - 2000 | 1,298 | 3,230 | 285,036,114 |
| Population - 1990 | 1,385 | 2,988 | 251,960,433 |
| Pop. 2000 to Now | -2.3% | 32.3% | 15.6% |
| Pop. 1990 to Now | -8.5% | 43.0% | 30.8% |
| space4 | | | |
| Population Density | 1,035.2 | 634.5 | 93.4 |
| Land Area | 1.6 | 6.2 | 3,531,905.4 |
| Water Area | 0.1 | 0.7 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Shell Rock, IA | Mulberry, FL | United States |
| Age 0 to 4 | 10.5% | 3.3% | 5.9% |
| Age 5 to 9 | 7.1% | 5.0% | 6.1% |
| Age 10 to 14 | 9.3% | 4.1% | 6.6% |
| Age 15 to 17 | 2.5% | 2.6% | 3.9% |
| Age 18 to 20 | 2.5% | 3.8% | 4.0% |
| Age 21 to 24 | 2.7% | 2.9% | 5.2% |
| Age 25 to 34 | 16.8% | 12.6% | 13.8% |
| Age 35 to 44 | 11.9% | 11.7% | 12.9% |
| Age 45 to 54 | 8.8% | 12.8% | 12.6% |
| Age 55 to 59 | 3.2% | 5.6% | 6.7% |
| Age 60 to 64 | 8.0% | 3.2% | 6.3% |
| Age 65 to 74 | 8.9% | 19.7% | 9.6% |
| Age 75 to 84 | 3.4% | 11.1% | 4.5% |
| Age 85 and over | 4.3% | 1.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Shell Rock, IA | Mulberry, FL | United States |
| White | 98.9% | 68.3% | 59.4% |
| Black | 0.4% | 13.6% | 12.2% |
| Asian | 0.4% | 2.5% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 0.2% | 2.2% | 3.2% |
| Hispanic | 0.1% | 13.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Shell Rock, IA | Mulberry, FL | United States |
| Married Population | 64.9% | 54.8% | 49.8% |
| Currently Married | 63.9% | 53.4% | 48.0% |
| Married but Separated | 1.0% | 1.4% | 1.8% |
| Single Population | 35.1% | 45.2% | 50.2% |
| Never Married | 19.6% | 23.1% | 33.8% |
| Divorced | 7.7% | 14.1% | 10.8% |
| Widowed | 7.8% | 8.0% | 5.6% |
| space5 | | | |
| Household Size | 2.58 | 2.41 | 2.60 |
| Households | 612 | 1,627 | 124,010,992 |
| Family Households | 430 | 1,067 | 80,755,759 |
| Married couple, w/children | 45.6% | 18.7% | 30.5% |
| Married couple, no children | 37.7% | 59.0% | 42.9% |
| Non Family Households | 182 | 560 | 43,255,233 |
| Single householder, w/children | 11.2% | 15.5% | 15.8% |
| Single householder, no children | 5.6% | 6.8% | 10.8% |