| | Sydney, ND | Cairo, GA | United States |
| Population | 151 | 10,095 | 329,725,481 |
| Female Population | 51.7% | 52.3% | 50.5% |
| Male Population | 48.3% | 47.7% | 49.5% |
| Median Age | 39.4 | 34.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 78 | 9,640 | 309,327,143 |
| Population - 2000 | 93 | 9,239 | 285,036,114 |
| Population - 1990 | 92 | 9,035 | 251,960,433 |
| Pop. 2000 to Now | -19.4% | 0.7% | 15.6% |
| Pop. 1990 to Now | -18.5% | 3.0% | 30.8% |
| space4 | | | |
| Population Density | 4.2 | 1,037.0 | 93.4 |
| Land Area | 36.1 | 9.7 | 3,531,905.4 |
| Water Area | 0.1 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Sydney, ND | Cairo, GA | United States |
| Age 0 to 4 | 0.0% | 3.1% | 5.9% |
| Age 5 to 9 | 0.0% | 11.1% | 6.1% |
| Age 10 to 14 | 25.2% | 8.6% | 6.6% |
| Age 15 to 17 | 19.2% | 5.4% | 3.9% |
| Age 18 to 20 | 0.0% | 3.0% | 4.0% |
| Age 21 to 24 | 0.0% | 6.2% | 5.2% |
| Age 25 to 34 | 0.0% | 12.6% | 13.8% |
| Age 35 to 44 | 30.5% | 11.7% | 12.9% |
| Age 45 to 54 | 10.6% | 9.3% | 12.6% |
| Age 55 to 59 | 2.0% | 7.9% | 6.7% |
| Age 60 to 64 | 0.0% | 5.3% | 6.3% |
| Age 65 to 74 | 12.6% | 8.0% | 9.6% |
| Age 75 to 84 | 0.0% | 5.7% | 4.5% |
| Age 85 and over | 0.0% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Sydney, ND | Cairo, GA | United States |
| White | 100.0% | 34.7% | 59.4% |
| Black | 0.0% | 48.8% | 12.2% |
| Asian | 0.0% | 0.7% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.0% | 2.0% | 3.2% |
| Hispanic | 0.0% | 13.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Sydney, ND | Cairo, GA | United States |
| Married Population | 57.5% | 40.3% | 49.8% |
| Currently Married | 57.5% | 35.9% | 48.0% |
| Married but Separated | 0.0% | 4.4% | 1.8% |
| Single Population | 42.5% | 59.7% | 50.2% |
| Never Married | 42.5% | 36.6% | 33.8% |
| Divorced | 0.0% | 14.8% | 10.8% |
| Widowed | 0.0% | 8.2% | 5.6% |
| space5 | | | |
| Household Size | 3.08 | 2.72 | 2.60 |
| Households | 49 | 3,690 | 124,010,992 |
| Family Households | 46 | 2,190 | 80,755,759 |
| Married couple, w/children | 47.8% | 23.6% | 30.5% |
| Married couple, no children | 17.4% | 28.9% | 42.9% |
| Non Family Households | 3 | 1,500 | 43,255,233 |
| Single householder, w/children | 34.8% | 30.1% | 15.8% |
| Single householder, no children | 0.0% | 17.4% | 10.8% |