| | Guilford, ME | Romney, WV | United States |
| Population | 1,031 | 2,035 | 329,725,481 |
| Female Population | 47.3% | 51.7% | 50.5% |
| Male Population | 52.7% | 48.3% | 49.5% |
| Median Age | 58 | 40.4 | 38.4 |
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| Population - 2010 | 1,526 | 1,835 | 309,327,143 |
| Population - 2000 | 1,531 | 1,940 | 285,036,114 |
| Population - 1990 | 1,710 | 1,966 | 251,960,433 |
| Pop. 2000 to Now | -4.1% | -13.4% | 15.6% |
| Pop. 1990 to Now | -14.2% | -14.6% | 30.8% |
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| Population Density | 29.6 | 2,117.6 | 93.4 |
| Land Area | 34.9 | 1.0 | 3,531,905.4 |
| Water Area | 0.8 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Guilford, ME | Romney, WV | United States |
| Age 0 to 4 | 4.8% | 1.7% | 5.9% |
| Age 5 to 9 | 3.7% | 7.7% | 6.1% |
| Age 10 to 14 | 1.6% | 16.7% | 6.6% |
| Age 15 to 17 | 5.0% | 10.3% | 3.9% |
| Age 18 to 20 | 1.4% | 3.1% | 4.0% |
| Age 21 to 24 | 0.0% | 2.2% | 5.2% |
| Age 25 to 34 | 7.9% | 3.6% | 13.8% |
| Age 35 to 44 | 8.0% | 7.1% | 12.9% |
| Age 45 to 54 | 14.3% | 18.3% | 12.6% |
| Age 55 to 59 | 9.7% | 5.7% | 6.7% |
| Age 60 to 64 | 11.8% | 3.1% | 6.3% |
| Age 65 to 74 | 20.0% | 8.4% | 9.6% |
| Age 75 to 84 | 9.2% | 7.1% | 4.5% |
| Age 85 and over | 2.8% | 5.2% | 1.9% |
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| Race | | | |
| | Guilford, ME | Romney, WV | United States |
| White | 96.0% | 74.2% | 59.4% |
| Black | 0.0% | 1.7% | 12.2% |
| Asian | 4.0% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.0% | 17.4% | 3.2% |
| Hispanic | 0.0% | 6.8% | 18.4% |
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| Marriage & Family | | | |
| | Guilford, ME | Romney, WV | United States |
| Married Population | 55.6% | 24.8% | 49.8% |
| Currently Married | 54.4% | 21.5% | 48.0% |
| Married but Separated | 1.2% | 3.3% | 1.8% |
| Single Population | 44.4% | 75.2% | 50.2% |
| Never Married | 18.1% | 42.4% | 33.8% |
| Divorced | 23.0% | 21.0% | 10.8% |
| Widowed | 3.3% | 11.8% | 5.6% |
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| Household Size | 2.28 | 2.78 | 2.60 |
| Households | 452 | 662 | 124,010,992 |
| Family Households | 322 | 291 | 80,755,759 |
| Married couple, w/children | 5.3% | 23.0% | 30.5% |
| Married couple, no children | 64.9% | 30.2% | 42.9% |
| Non Family Households | 130 | 371 | 43,255,233 |
| Single householder, w/children | 18.6% | 26.5% | 15.8% |
| Single householder, no children | 11.2% | 20.3% | 10.8% |