| | Ashtabula, OH | Dunkirk, NY | United States |
| Population | 18,091 | 12,651 | 329,725,481 |
| Female Population | 53.2% | 49.0% | 50.5% |
| Male Population | 46.8% | 51.0% | 49.5% |
| Median Age | 40.5 | 42.4 | 38.4 |
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| Population - 2010 | 19,105 | 12,527 | 309,327,143 |
| Population - 2000 | 20,962 | 13,131 | 285,036,114 |
| Population - 1990 | 21,633 | 13,989 | 251,960,433 |
| Pop. 2000 to Now | -14.5% | -10.9% | 15.6% |
| Pop. 1990 to Now | -17.2% | -16.4% | 30.8% |
| space4 | | | |
| Population Density | 2,327.4 | 2,808.2 | 93.4 |
| Land Area | 7.8 | 4.5 | 3,531,905.4 |
| Water Area | 0.2 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Ashtabula, OH | Dunkirk, NY | United States |
| Age 0 to 4 | 6.4% | 5.3% | 5.9% |
| Age 5 to 9 | 6.3% | 6.0% | 6.1% |
| Age 10 to 14 | 6.3% | 5.0% | 6.6% |
| Age 15 to 17 | 4.1% | 2.7% | 3.9% |
| Age 18 to 20 | 2.9% | 3.3% | 4.0% |
| Age 21 to 24 | 4.7% | 6.0% | 5.2% |
| Age 25 to 34 | 13.2% | 12.8% | 13.8% |
| Age 35 to 44 | 11.6% | 11.7% | 12.9% |
| Age 45 to 54 | 12.8% | 11.9% | 12.6% |
| Age 55 to 59 | 6.4% | 7.6% | 6.7% |
| Age 60 to 64 | 6.7% | 9.7% | 6.3% |
| Age 65 to 74 | 10.5% | 11.6% | 9.6% |
| Age 75 to 84 | 5.8% | 4.7% | 4.5% |
| Age 85 and over | 2.4% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Ashtabula, OH | Dunkirk, NY | United States |
| White | 73.6% | 61.9% | 59.4% |
| Black | 8.3% | 6.9% | 12.2% |
| Asian | 0.5% | 0.1% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.9% | 0.0% | 0.4% |
| Two or More Races | 3.9% | 2.6% | 3.2% |
| Hispanic | 12.8% | 28.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Ashtabula, OH | Dunkirk, NY | United States |
| Married Population | 39.6% | 37.8% | 49.8% |
| Currently Married | 35.5% | 36.3% | 48.0% |
| Married but Separated | 4.1% | 1.6% | 1.8% |
| Single Population | 60.4% | 62.2% | 50.2% |
| Never Married | 35.1% | 41.5% | 33.8% |
| Divorced | 17.6% | 13.6% | 10.8% |
| Widowed | 7.8% | 7.1% | 5.6% |
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| Household Size | 2.33 | 2.11 | 2.60 |
| Households | 7,646 | 5,948 | 124,010,992 |
| Family Households | 4,294 | 3,256 | 80,755,759 |
| Married couple, w/children | 19.3% | 16.3% | 30.5% |
| Married couple, no children | 38.8% | 40.0% | 42.9% |
| Non Family Households | 3,352 | 2,692 | 43,255,233 |
| Single householder, w/children | 28.6% | 27.2% | 15.8% |
| Single householder, no children | 13.2% | 16.4% | 10.8% |