| | Murray, KY | Waterloo, IA | United States |
| Population | 17,241 | 67,695 | 329,725,481 |
| Female Population | 50.1% | 50.2% | 50.5% |
| Male Population | 49.9% | 49.8% | 49.5% |
| Median Age | 25.6 | 36.8 | 38.4 |
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| Population - 2010 | 17,835 | 68,488 | 309,327,143 |
| Population - 2000 | 14,950 | 68,747 | 285,036,114 |
| Population - 1990 | 14,439 | 66,467 | 251,960,433 |
| Pop. 2000 to Now | 30.0% | -2.1% | 15.6% |
| Pop. 1990 to Now | 34.6% | 1.2% | 30.8% |
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| Population Density | 1,484.9 | 1,100.9 | 93.4 |
| Land Area | 11.6 | 61.5 | 3,531,905.4 |
| Water Area | 0.0 | 1.7 | 264,836.8 |
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| Est. Total Population By Age | | | |
| | Murray, KY | Waterloo, IA | United States |
| Age 0 to 4 | 3.7% | 7.1% | 5.9% |
| Age 5 to 9 | 3.9% | 6.6% | 6.1% |
| Age 10 to 14 | 3.8% | 6.2% | 6.6% |
| Age 15 to 17 | 2.3% | 4.0% | 3.9% |
| Age 18 to 20 | 20.2% | 3.4% | 4.0% |
| Age 21 to 24 | 15.0% | 5.8% | 5.2% |
| Age 25 to 34 | 12.5% | 14.3% | 13.8% |
| Age 35 to 44 | 8.9% | 12.4% | 12.9% |
| Age 45 to 54 | 9.2% | 11.3% | 12.6% |
| Age 55 to 59 | 4.8% | 6.0% | 6.7% |
| Age 60 to 64 | 3.6% | 6.8% | 6.3% |
| Age 65 to 74 | 6.1% | 9.8% | 9.6% |
| Age 75 to 84 | 4.4% | 4.4% | 4.5% |
| Age 85 and over | 1.7% | 2.1% | 1.9% |
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| Race | | | |
| | Murray, KY | Waterloo, IA | United States |
| White | 84.5% | 68.9% | 59.4% |
| Black | 6.5% | 17.1% | 12.2% |
| Asian | 3.1% | 2.5% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.5% | 0.4% | 0.2% |
| Other | 0.4% | 0.1% | 0.4% |
| Two or More Races | 3.1% | 3.7% | 3.2% |
| Hispanic | 1.9% | 7.1% | 18.4% |
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| Marriage & Family | | | |
| | Murray, KY | Waterloo, IA | United States |
| Married Population | 31.9% | 45.5% | 49.8% |
| Currently Married | 30.5% | 43.8% | 48.0% |
| Married but Separated | 1.4% | 1.7% | 1.8% |
| Single Population | 68.1% | 54.5% | 50.2% |
| Never Married | 53.9% | 37.5% | 33.8% |
| Divorced | 9.7% | 11.6% | 10.8% |
| Widowed | 4.5% | 5.4% | 5.6% |
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| Household Size | 2.15 | 2.31 | 2.60 |
| Households | 6,341 | 28,912 | 124,010,992 |
| Family Households | 3,053 | 16,798 | 80,755,759 |
| Married couple, w/children | 31.1% | 26.4% | 30.5% |
| Married couple, no children | 40.2% | 41.6% | 42.9% |
| Non Family Households | 3,288 | 12,114 | 43,255,233 |
| Single householder, w/children | 22.8% | 22.6% | 15.8% |
| Single householder, no children | 5.9% | 9.4% | 10.8% |