| | Bethany, OR | South Riding, VA | United States |
| Population | 29,277 | 33,828 | 329,725,481 |
| Female Population | 49.4% | 49.0% | 50.5% |
| Male Population | 50.7% | 51.0% | 49.5% |
| Median Age | 37.1 | 36.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 19,475 | 22,982 | 309,327,143 |
| Population - 2000 | 13,038 | 6,307 | 285,036,114 |
| Population - 1990 | 1,136 | 1,369 | 251,960,433 |
| Pop. 2000 to Now | 87.2% | 445.1% | 15.6% |
| Pop. 1990 to Now | 2,049.0% | 2,411.3% | 30.8% |
| space4 | | | |
| Population Density | 5,378.8 | 4,934.8 | 93.4 |
| Land Area | 5.4 | 6.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Bethany, OR | South Riding, VA | United States |
| Age 0 to 4 | 6.0% | 6.0% | 5.9% |
| Age 5 to 9 | 9.6% | 9.1% | 6.1% |
| Age 10 to 14 | 10.3% | 9.9% | 6.6% |
| Age 15 to 17 | 4.7% | 5.2% | 3.9% |
| Age 18 to 20 | 2.3% | 3.9% | 4.0% |
| Age 21 to 24 | 1.8% | 2.4% | 5.2% |
| Age 25 to 34 | 11.1% | 10.8% | 13.8% |
| Age 35 to 44 | 19.5% | 20.2% | 12.9% |
| Age 45 to 54 | 16.7% | 17.5% | 12.6% |
| Age 55 to 59 | 5.1% | 6.1% | 6.7% |
| Age 60 to 64 | 3.8% | 3.6% | 6.3% |
| Age 65 to 74 | 4.4% | 3.7% | 9.6% |
| Age 75 to 84 | 3.5% | 1.4% | 4.5% |
| Age 85 and over | 1.1% | 0.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Bethany, OR | South Riding, VA | United States |
| White | 46.1% | 41.4% | 59.4% |
| Black | 2.2% | 8.1% | 12.2% |
| Asian | 40.5% | 35.3% | 5.6% |
| Native American | 0.2% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.4% | 0.0% | 0.2% |
| Other | 0.9% | 1.5% | 0.4% |
| Two or More Races | 4.7% | 4.4% | 3.2% |
| Hispanic | 5.0% | 9.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Bethany, OR | South Riding, VA | United States |
| Married Population | 66.4% | 68.7% | 49.8% |
| Currently Married | 65.9% | 67.5% | 48.0% |
| Married but Separated | 0.5% | 1.2% | 1.8% |
| Single Population | 33.6% | 31.3% | 50.2% |
| Never Married | 22.3% | 23.5% | 33.8% |
| Divorced | 8.2% | 5.6% | 10.8% |
| Widowed | 3.1% | 2.2% | 5.6% |
| space5 | | | |
| Household Size | 2.92 | 3.27 | 2.60 |
| Households | 10,017 | 10,353 | 124,010,992 |
| Family Households | 8,060 | 9,075 | 80,755,759 |
| Married couple, w/children | 53.3% | 56.6% | 30.5% |
| Married couple, no children | 32.2% | 30.1% | 42.9% |
| Non Family Households | 1,957 | 1,278 | 43,255,233 |
| Single householder, w/children | 9.5% | 9.5% | 15.8% |
| Single householder, no children | 5.1% | 3.7% | 10.8% |