| | Hornbrook, CA | Etna, CA | United States |
| Population | 303 | 753 | 329,725,481 |
| Female Population | 63.4% | 51.4% | 50.5% |
| Male Population | 36.6% | 48.6% | 49.5% |
| Median Age | 45.8 | 41.6 | 38.4 |
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| Population - 2010 | 270 | 739 | 309,327,143 |
| Population - 2000 | 286 | 781 | 285,036,114 |
| Population - 1990 | 242 | 835 | 251,960,433 |
| Pop. 2000 to Now | -24.5% | -9.6% | 15.6% |
| Pop. 1990 to Now | -10.7% | -15.5% | 30.8% |
| space4 | | | |
| Population Density | 260.1 | 990.8 | 93.4 |
| Land Area | 1.2 | 0.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Hornbrook, CA | Etna, CA | United States |
| Age 0 to 4 | 5.3% | 11.7% | 5.9% |
| Age 5 to 9 | 2.0% | 2.3% | 6.1% |
| Age 10 to 14 | 9.2% | 8.1% | 6.6% |
| Age 15 to 17 | 5.6% | 2.8% | 3.9% |
| Age 18 to 20 | 1.0% | 3.2% | 4.0% |
| Age 21 to 24 | 5.9% | 0.7% | 5.2% |
| Age 25 to 34 | 1.7% | 12.5% | 13.8% |
| Age 35 to 44 | 15.5% | 15.3% | 12.9% |
| Age 45 to 54 | 16.5% | 14.9% | 12.6% |
| Age 55 to 59 | 1.7% | 0.0% | 6.7% |
| Age 60 to 64 | 5.6% | 5.7% | 6.3% |
| Age 65 to 74 | 17.8% | 16.6% | 9.6% |
| Age 75 to 84 | 9.6% | 5.4% | 4.5% |
| Age 85 and over | 2.6% | 0.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Hornbrook, CA | Etna, CA | United States |
| White | 85.5% | 77.8% | 59.4% |
| Black | 0.0% | 4.1% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.0% | 4.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 10.2% | 8.0% | 3.2% |
| Hispanic | 4.3% | 6.0% | 18.4% |
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| Marriage & Family | | | |
| | Hornbrook, CA | Etna, CA | United States |
| Married Population | 31.6% | 43.1% | 49.8% |
| Currently Married | 31.6% | 40.5% | 48.0% |
| Married but Separated | 0.0% | 2.6% | 1.8% |
| Single Population | 68.4% | 56.9% | 50.2% |
| Never Married | 35.2% | 30.2% | 33.8% |
| Divorced | 30.8% | 23.3% | 10.8% |
| Widowed | 2.4% | 3.4% | 5.6% |
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| Household Size | 2.39 | 2.50 | 2.60 |
| Households | 127 | 295 | 124,010,992 |
| Family Households | 59 | 187 | 80,755,759 |
| Married couple, w/children | 8.5% | 27.8% | 30.5% |
| Married couple, no children | 40.7% | 34.8% | 42.9% |
| Non Family Households | 68 | 108 | 43,255,233 |
| Single householder, w/children | 50.8% | 20.9% | 15.8% |
| Single householder, no children | 0.0% | 16.6% | 10.8% |