| | Holbrook, NY | Deerpark, NY | United States |
| Population | 26,958 | 7,574 | 329,725,481 |
| Female Population | 52.9% | 53.6% | 50.5% |
| Male Population | 47.1% | 46.4% | 49.5% |
| Median Age | 40.4 | 42.1 | 38.4 |
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| Population - 2010 | 26,981 | 7,927 | 309,327,143 |
| Population - 2000 | 27,512 | 7,858 | 285,036,114 |
| Population - 1990 | 25,273 | 7,832 | 251,960,433 |
| Pop. 2000 to Now | -6.2% | -2.1% | 15.6% |
| Pop. 1990 to Now | 2.1% | -1.8% | 30.8% |
| space4 | | | |
| Population Density | 3,757.7 | 113.9 | 93.4 |
| Land Area | 7.2 | 66.5 | 3,531,905.4 |
| Water Area | 0.0 | 1.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Holbrook, NY | Deerpark, NY | United States |
| Age 0 to 4 | 5.6% | 5.0% | 5.9% |
| Age 5 to 9 | 5.7% | 5.7% | 6.1% |
| Age 10 to 14 | 6.4% | 6.8% | 6.6% |
| Age 15 to 17 | 4.6% | 4.8% | 3.9% |
| Age 18 to 20 | 3.3% | 3.6% | 4.0% |
| Age 21 to 24 | 4.4% | 3.8% | 5.2% |
| Age 25 to 34 | 13.9% | 10.6% | 13.8% |
| Age 35 to 44 | 12.2% | 14.4% | 12.9% |
| Age 45 to 54 | 13.6% | 12.9% | 12.6% |
| Age 55 to 59 | 7.1% | 7.8% | 6.7% |
| Age 60 to 64 | 7.6% | 6.7% | 6.3% |
| Age 65 to 74 | 10.1% | 14.6% | 9.6% |
| Age 75 to 84 | 4.5% | 2.7% | 4.5% |
| Age 85 and over | 0.9% | 0.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Holbrook, NY | Deerpark, NY | United States |
| White | 76.1% | 73.3% | 59.4% |
| Black | 4.2% | 6.6% | 12.2% |
| Asian | 3.7% | 2.0% | 5.6% |
| Native American | 0.2% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.3% | 0.0% | 0.4% |
| Two or More Races | 1.3% | 10.1% | 3.2% |
| Hispanic | 14.3% | 7.6% | 18.4% |
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| Marriage & Family | | | |
| | Holbrook, NY | Deerpark, NY | United States |
| Married Population | 52.9% | 48.9% | 49.8% |
| Currently Married | 51.8% | 46.3% | 48.0% |
| Married but Separated | 1.1% | 2.6% | 1.8% |
| Single Population | 47.1% | 51.1% | 50.2% |
| Never Married | 33.1% | 33.4% | 33.8% |
| Divorced | 8.8% | 12.3% | 10.8% |
| Widowed | 5.2% | 5.5% | 5.6% |
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| Household Size | 3.01 | 2.70 | 2.60 |
| Households | 8,946 | 2,800 | 124,010,992 |
| Family Households | 6,722 | 1,845 | 80,755,759 |
| Married couple, w/children | 34.0% | 27.3% | 30.5% |
| Married couple, no children | 42.8% | 45.7% | 42.9% |
| Non Family Households | 2,224 | 955 | 43,255,233 |
| Single householder, w/children | 11.0% | 13.6% | 15.8% |
| Single householder, no children | 12.2% | 13.4% | 10.8% |