| | Santa Rosa, CA | West Chester, PA | United States |
| Population | 179,213 | 18,592 | 329,725,481 |
| Female Population | 51.4% | 52.4% | 50.5% |
| Male Population | 48.6% | 47.6% | 49.5% |
| Median Age | 40 | 24.6 | 38.4 |
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| Population - 2010 | 175,221 | 18,472 | 309,327,143 |
| Population - 2000 | 147,595 | 17,861 | 285,036,114 |
| Population - 1990 | 113,313 | 18,041 | 251,960,433 |
| Pop. 2000 to Now | 18.3% | 12.2% | 15.6% |
| Pop. 1990 to Now | 54.1% | 11.1% | 30.8% |
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| Population Density | 4,215.9 | 10,071.5 | 93.4 |
| Land Area | 42.5 | 1.8 | 3,531,905.4 |
| Water Area | 0.2 | 0.0 | 264,836.8 |
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| Est. Total Population By Age | | | |
| | Santa Rosa, CA | West Chester, PA | United States |
| Age 0 to 4 | 5.0% | 2.9% | 5.9% |
| Age 5 to 9 | 5.8% | 2.6% | 6.1% |
| Age 10 to 14 | 6.4% | 2.7% | 6.6% |
| Age 15 to 17 | 3.9% | 2.1% | 3.9% |
| Age 18 to 20 | 3.5% | 24.7% | 4.0% |
| Age 21 to 24 | 4.7% | 16.5% | 5.2% |
| Age 25 to 34 | 13.7% | 18.8% | 13.8% |
| Age 35 to 44 | 13.8% | 7.6% | 12.9% |
| Age 45 to 54 | 12.9% | 7.3% | 12.6% |
| Age 55 to 59 | 6.6% | 3.4% | 6.7% |
| Age 60 to 64 | 6.0% | 2.7% | 6.3% |
| Age 65 to 74 | 10.6% | 5.8% | 9.6% |
| Age 75 to 84 | 4.8% | 1.9% | 4.5% |
| Age 85 and over | 2.4% | 0.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Santa Rosa, CA | West Chester, PA | United States |
| White | 53.8% | 71.5% | 59.4% |
| Black | 1.9% | 12.1% | 12.2% |
| Asian | 5.8% | 1.7% | 5.6% |
| Native American | 0.3% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.4% | 0.0% | 0.2% |
| Other | 0.4% | 0.1% | 0.4% |
| Two or More Races | 3.4% | 2.4% | 3.2% |
| Hispanic | 34.0% | 12.4% | 18.4% |
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| Marriage & Family | | | |
| | Santa Rosa, CA | West Chester, PA | United States |
| Married Population | 48.4% | 21.1% | 49.8% |
| Currently Married | 46.4% | 19.6% | 48.0% |
| Married but Separated | 2.0% | 1.5% | 1.8% |
| Single Population | 51.6% | 78.9% | 50.2% |
| Never Married | 33.8% | 67.4% | 33.8% |
| Divorced | 12.3% | 8.1% | 10.8% |
| Widowed | 5.4% | 3.4% | 5.6% |
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| Household Size | 2.60 | 2.18 | 2.60 |
| Households | 67,662 | 6,832 | 124,010,992 |
| Family Households | 42,220 | 2,394 | 80,755,759 |
| Married couple, w/children | 32.1% | 22.3% | 30.5% |
| Married couple, no children | 41.8% | 40.8% | 42.9% |
| Non Family Households | 25,442 | 4,438 | 43,255,233 |
| Single householder, w/children | 15.4% | 20.0% | 15.8% |
| Single householder, no children | 10.7% | 17.0% | 10.8% |