| | Riva, MD | Greenwood, IN | United States |
| Population | 4,477 | 62,914 | 329,725,481 |
| Female Population | 47.6% | 50.9% | 50.5% |
| Male Population | 52.4% | 49.1% | 49.5% |
| Median Age | 46 | 35.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,927 | 51,153 | 309,327,143 |
| Population - 2000 | 3,966 | 36,037 | 285,036,114 |
| Population - 1990 | 3,438 | 26,265 | 251,960,433 |
| Pop. 2000 to Now | -0.8% | 67.3% | 15.6% |
| Pop. 1990 to Now | 14.5% | 129.5% | 30.8% |
| space4 | | | |
| Population Density | 1,822.1 | 2,254.4 | 93.4 |
| Land Area | 2.5 | 27.9 | 3,531,905.4 |
| Water Area | 0.4 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Riva, MD | Greenwood, IN | United States |
| Age 0 to 4 | 6.1% | 7.0% | 5.9% |
| Age 5 to 9 | 3.5% | 6.9% | 6.1% |
| Age 10 to 14 | 7.6% | 7.9% | 6.6% |
| Age 15 to 17 | 5.1% | 3.6% | 3.9% |
| Age 18 to 20 | 2.7% | 3.3% | 4.0% |
| Age 21 to 24 | 2.8% | 4.9% | 5.2% |
| Age 25 to 34 | 8.4% | 15.3% | 13.8% |
| Age 35 to 44 | 12.2% | 14.0% | 12.9% |
| Age 45 to 54 | 16.7% | 11.0% | 12.6% |
| Age 55 to 59 | 7.6% | 6.3% | 6.7% |
| Age 60 to 64 | 6.5% | 4.9% | 6.3% |
| Age 65 to 74 | 15.2% | 9.2% | 9.6% |
| Age 75 to 84 | 4.5% | 3.8% | 4.5% |
| Age 85 and over | 1.3% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Riva, MD | Greenwood, IN | United States |
| White | 91.8% | 80.2% | 59.4% |
| Black | 1.3% | 4.4% | 12.2% |
| Asian | 0.4% | 6.1% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.2% | 0.4% |
| Two or More Races | 1.1% | 1.9% | 3.2% |
| Hispanic | 5.4% | 7.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Riva, MD | Greenwood, IN | United States |
| Married Population | 68.5% | 51.6% | 49.8% |
| Currently Married | 68.0% | 51.0% | 48.0% |
| Married but Separated | 0.5% | 0.6% | 1.8% |
| Single Population | 31.5% | 48.4% | 50.2% |
| Never Married | 19.9% | 28.7% | 33.8% |
| Divorced | 8.0% | 13.8% | 10.8% |
| Widowed | 3.5% | 5.8% | 5.6% |
| space5 | | | |
| Household Size | 2.80 | 2.47 | 2.60 |
| Households | 1,600 | 25,212 | 124,010,992 |
| Family Households | 1,315 | 16,466 | 80,755,759 |
| Married couple, w/children | 42.6% | 31.2% | 30.5% |
| Married couple, no children | 51.0% | 40.4% | 42.9% |
| Non Family Households | 285 | 8,746 | 43,255,233 |
| Single householder, w/children | 1.5% | 20.8% | 15.8% |
| Single householder, no children | 4.9% | 7.5% | 10.8% |