| | Hockessin, DE | South Valley Stream, NY | United States |
| Population | 13,464 | 6,754 | 329,725,481 |
| Female Population | 52.7% | 51.1% | 50.5% |
| Male Population | 47.3% | 48.9% | 49.5% |
| Median Age | 45.8 | 40.7 | 38.4 |
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| Population - 2010 | 12,919 | 5,263 | 309,327,143 |
| Population - 2000 | 12,902 | 5,638 | 285,036,114 |
| Population - 1990 | 10,051 | 5,328 | 251,960,433 |
| Pop. 2000 to Now | 7.4% | 22.5% | 15.6% |
| Pop. 1990 to Now | 37.9% | 29.6% | 30.8% |
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| Population Density | 1,340.9 | 7,763.2 | 93.4 |
| Land Area | 10.0 | 0.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
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| Est. Total Population By Age | | | |
| | Hockessin, DE | South Valley Stream, NY | United States |
| Age 0 to 4 | 6.3% | 3.3% | 5.9% |
| Age 5 to 9 | 6.3% | 7.1% | 6.1% |
| Age 10 to 14 | 7.0% | 10.7% | 6.6% |
| Age 15 to 17 | 4.0% | 3.8% | 3.9% |
| Age 18 to 20 | 2.7% | 3.7% | 4.0% |
| Age 21 to 24 | 2.3% | 4.1% | 5.2% |
| Age 25 to 34 | 7.5% | 12.3% | 13.8% |
| Age 35 to 44 | 13.0% | 10.1% | 12.9% |
| Age 45 to 54 | 14.8% | 12.6% | 12.6% |
| Age 55 to 59 | 6.8% | 6.3% | 6.7% |
| Age 60 to 64 | 7.1% | 6.8% | 6.3% |
| Age 65 to 74 | 14.0% | 8.0% | 9.6% |
| Age 75 to 84 | 5.3% | 7.1% | 4.5% |
| Age 85 and over | 2.9% | 4.2% | 1.9% |
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| Race | | | |
| | Hockessin, DE | South Valley Stream, NY | United States |
| White | 82.3% | 30.8% | 59.4% |
| Black | 2.7% | 24.7% | 12.2% |
| Asian | 9.0% | 19.8% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.6% | 1.6% | 0.4% |
| Two or More Races | 3.7% | 5.6% | 3.2% |
| Hispanic | 1.7% | 17.5% | 18.4% |
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| Marriage & Family | | | |
| | Hockessin, DE | South Valley Stream, NY | United States |
| Married Population | 68.0% | 53.2% | 49.8% |
| Currently Married | 67.6% | 52.0% | 48.0% |
| Married but Separated | 0.4% | 1.2% | 1.8% |
| Single Population | 32.0% | 46.8% | 50.2% |
| Never Married | 21.1% | 33.1% | 33.8% |
| Divorced | 5.2% | 5.3% | 10.8% |
| Widowed | 5.7% | 8.3% | 5.6% |
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| Household Size | 2.75 | 3.56 | 2.60 |
| Households | 4,782 | 1,896 | 124,010,992 |
| Family Households | 4,101 | 1,544 | 80,755,759 |
| Married couple, w/children | 38.0% | 36.7% | 30.5% |
| Married couple, no children | 51.2% | 41.5% | 42.9% |
| Non Family Households | 681 | 352 | 43,255,233 |
| Single householder, w/children | 5.9% | 11.7% | 15.8% |
| Single householder, no children | 4.9% | 10.2% | 10.8% |