| | Wellsville, NY | Portales, NM | United States |
| Population | 7,124 | 12,151 | 329,725,481 |
| Female Population | 50.7% | 51.0% | 50.5% |
| Male Population | 49.3% | 49.0% | 49.5% |
| Median Age | 49.1 | 27.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 7,397 | 12,404 | 309,327,143 |
| Population - 2000 | 7,678 | 11,131 | 285,036,114 |
| Population - 1990 | 8,116 | 10,690 | 251,960,433 |
| Pop. 2000 to Now | -10.8% | 3.2% | 15.6% |
| Pop. 1990 to Now | -15.6% | 7.5% | 30.8% |
| space4 | | | |
| Population Density | 194.4 | 1,535.4 | 93.4 |
| Land Area | 36.6 | 7.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Wellsville, NY | Portales, NM | United States |
| Age 0 to 4 | 5.8% | 6.4% | 5.9% |
| Age 5 to 9 | 4.4% | 8.6% | 6.1% |
| Age 10 to 14 | 4.4% | 6.9% | 6.6% |
| Age 15 to 17 | 3.1% | 4.1% | 3.9% |
| Age 18 to 20 | 4.8% | 9.0% | 4.0% |
| Age 21 to 24 | 3.5% | 12.5% | 5.2% |
| Age 25 to 34 | 7.7% | 12.5% | 13.8% |
| Age 35 to 44 | 11.1% | 11.9% | 12.9% |
| Age 45 to 54 | 10.8% | 7.3% | 12.6% |
| Age 55 to 59 | 10.1% | 4.0% | 6.7% |
| Age 60 to 64 | 8.3% | 4.1% | 6.3% |
| Age 65 to 74 | 13.9% | 8.1% | 9.6% |
| Age 75 to 84 | 6.4% | 3.0% | 4.5% |
| Age 85 and over | 5.7% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Wellsville, NY | Portales, NM | United States |
| White | 96.3% | 45.9% | 59.4% |
| Black | 0.7% | 3.2% | 12.2% |
| Asian | 0.0% | 0.7% | 5.6% |
| Native American | 0.4% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 0.6% | 0.4% |
| Two or More Races | 2.2% | 3.7% | 3.2% |
| Hispanic | 0.4% | 45.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Wellsville, NY | Portales, NM | United States |
| Married Population | 46.8% | 39.4% | 49.8% |
| Currently Married | 45.1% | 36.8% | 48.0% |
| Married but Separated | 1.7% | 2.6% | 1.8% |
| Single Population | 53.2% | 60.6% | 50.2% |
| Never Married | 27.8% | 42.2% | 33.8% |
| Divorced | 14.9% | 11.5% | 10.8% |
| Widowed | 10.5% | 6.9% | 5.6% |
| space5 | | | |
| Household Size | 2.16 | 2.63 | 2.60 |
| Households | 3,164 | 4,273 | 124,010,992 |
| Family Households | 1,652 | 2,314 | 80,755,759 |
| Married couple, w/children | 22.8% | 36.1% | 30.5% |
| Married couple, no children | 53.1% | 33.2% | 42.9% |
| Non Family Households | 1,512 | 1,959 | 43,255,233 |
| Single householder, w/children | 17.3% | 22.9% | 15.8% |
| Single householder, no children | 6.7% | 7.8% | 10.8% |