| | Bethlehem, NY | Natick, MA | United States |
| Population | 34,981 | 36,627 | 329,725,481 |
| Female Population | 51.6% | 51.7% | 50.5% |
| Male Population | 48.4% | 48.3% | 49.5% |
| Median Age | 44.1 | 42.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 33,640 | 33,100 | 309,327,143 |
| Population - 2000 | 31,304 | 32,170 | 285,036,114 |
| Population - 1990 | 27,552 | 30,510 | 251,960,433 |
| Pop. 2000 to Now | 11.2% | 11.2% | 15.6% |
| Pop. 1990 to Now | 26.3% | 17.2% | 30.8% |
| space4 | | | |
| Population Density | 713.5 | 2,449.3 | 93.4 |
| Land Area | 49.0 | 15.0 | 3,531,905.4 |
| Water Area | 0.8 | 1.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Bethlehem, NY | Natick, MA | United States |
| Age 0 to 4 | 5.4% | 5.3% | 5.9% |
| Age 5 to 9 | 5.1% | 7.1% | 6.1% |
| Age 10 to 14 | 6.7% | 5.5% | 6.6% |
| Age 15 to 17 | 3.9% | 4.3% | 3.9% |
| Age 18 to 20 | 3.7% | 1.9% | 4.0% |
| Age 21 to 24 | 4.2% | 3.2% | 5.2% |
| Age 25 to 34 | 9.9% | 12.9% | 13.8% |
| Age 35 to 44 | 12.2% | 13.0% | 12.9% |
| Age 45 to 54 | 15.5% | 14.9% | 12.6% |
| Age 55 to 59 | 8.1% | 7.0% | 6.7% |
| Age 60 to 64 | 6.6% | 7.2% | 6.3% |
| Age 65 to 74 | 10.1% | 10.6% | 9.6% |
| Age 75 to 84 | 5.4% | 4.7% | 4.5% |
| Age 85 and over | 3.1% | 2.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Bethlehem, NY | Natick, MA | United States |
| White | 87.5% | 76.9% | 59.4% |
| Black | 2.7% | 1.9% | 12.2% |
| Asian | 4.0% | 14.0% | 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 | 1.7% | 2.8% | 3.2% |
| Hispanic | 3.9% | 4.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Bethlehem, NY | Natick, MA | United States |
| Married Population | 57.7% | 59.7% | 49.8% |
| Currently Married | 57.0% | 58.1% | 48.0% |
| Married but Separated | 0.7% | 1.6% | 1.8% |
| Single Population | 42.3% | 40.3% | 50.2% |
| Never Married | 27.2% | 25.7% | 33.8% |
| Divorced | 8.8% | 9.4% | 10.8% |
| Widowed | 6.2% | 5.2% | 5.6% |
| space5 | | | |
| Household Size | 2.41 | 2.38 | 2.60 |
| Households | 14,328 | 15,243 | 124,010,992 |
| Family Households | 9,428 | 10,143 | 80,755,759 |
| Married couple, w/children | 36.5% | 39.6% | 30.5% |
| Married couple, no children | 49.2% | 44.3% | 42.9% |
| Non Family Households | 4,900 | 5,100 | 43,255,233 |
| Single householder, w/children | 7.7% | 8.1% | 15.8% |
| Single householder, no children | 6.6% | 8.0% | 10.8% |