| | New Castle, PA | Avon, OH | United States |
| Population | 21,992 | 24,542 | 329,725,481 |
| Female Population | 53.7% | 51.7% | 50.5% |
| Male Population | 46.3% | 48.4% | 49.5% |
| Median Age | 39.1 | 41.4 | 38.4 |
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| Population - 2010 | 23,243 | 21,244 | 309,327,143 |
| Population - 2000 | 26,309 | 11,446 | 285,036,114 |
| Population - 1990 | 28,334 | 7,337 | 251,960,433 |
| Pop. 2000 to Now | -18.4% | 107.5% | 15.6% |
| Pop. 1990 to Now | -24.2% | 223.6% | 30.8% |
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| Population Density | 2,647.4 | 1,179.5 | 93.4 |
| Land Area | 8.3 | 20.8 | 3,531,905.4 |
| Water Area | 0.2 | 0.1 | 264,836.8 |
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| Est. Total Population By Age | | | |
| | New Castle, PA | Avon, OH | United States |
| Age 0 to 4 | 6.4% | 5.2% | 5.9% |
| Age 5 to 9 | 6.2% | 7.7% | 6.1% |
| Age 10 to 14 | 6.9% | 10.2% | 6.6% |
| Age 15 to 17 | 3.7% | 5.4% | 3.9% |
| Age 18 to 20 | 3.3% | 2.1% | 4.0% |
| Age 21 to 24 | 3.9% | 3.0% | 5.2% |
| Age 25 to 34 | 14.7% | 8.7% | 13.8% |
| Age 35 to 44 | 10.9% | 12.3% | 12.9% |
| Age 45 to 54 | 12.8% | 19.6% | 12.6% |
| Age 55 to 59 | 5.8% | 5.8% | 6.7% |
| Age 60 to 64 | 8.1% | 3.3% | 6.3% |
| Age 65 to 74 | 9.9% | 10.0% | 9.6% |
| Age 75 to 84 | 4.9% | 5.1% | 4.5% |
| Age 85 and over | 2.5% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | New Castle, PA | Avon, OH | United States |
| White | 77.6% | 86.4% | 59.4% |
| Black | 10.6% | 4.2% | 12.2% |
| Asian | 0.1% | 3.3% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.2% | 0.2% | 0.4% |
| Two or More Races | 7.3% | 1.3% | 3.2% |
| Hispanic | 4.2% | 4.3% | 18.4% |
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| Marriage & Family | | | |
| | New Castle, PA | Avon, OH | United States |
| Married Population | 38.0% | 65.2% | 49.8% |
| Currently Married | 35.2% | 64.7% | 48.0% |
| Married but Separated | 2.7% | 0.5% | 1.8% |
| Single Population | 62.0% | 34.8% | 50.2% |
| Never Married | 38.4% | 19.2% | 33.8% |
| Divorced | 15.0% | 7.7% | 10.8% |
| Widowed | 8.5% | 7.9% | 5.6% |
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| Household Size | 2.29 | 2.66 | 2.60 |
| Households | 9,248 | 9,137 | 124,010,992 |
| Family Households | 5,354 | 6,961 | 80,755,759 |
| Married couple, w/children | 19.0% | 44.4% | 30.5% |
| Married couple, no children | 36.4% | 41.6% | 42.9% |
| Non Family Households | 3,894 | 2,176 | 43,255,233 |
| Single householder, w/children | 30.4% | 9.2% | 15.8% |
| Single householder, no children | 14.2% | 4.8% | 10.8% |