| | Lake Barrington, IL | Flat Rock, NC | United States |
| Population | 5,557 | 3,460 | 329,725,481 |
| Female Population | 50.7% | 52.3% | 50.5% |
| Male Population | 49.3% | 47.7% | 49.5% |
| Median Age | 55.5 | 63.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 4,959 | 3,119 | 309,327,143 |
| Population - 2000 | 4,757 | 2,565 | 285,036,114 |
| Population - 1990 | 3,855 | 1,940 | 251,960,433 |
| Pop. 2000 to Now | 1.7% | 32.9% | 15.6% |
| Pop. 1990 to Now | 25.6% | 75.7% | 30.8% |
| space4 | | | |
| Population Density | 968.8 | 427.1 | 93.4 |
| Land Area | 5.7 | 8.1 | 3,531,905.4 |
| Water Area | 0.3 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lake Barrington, IL | Flat Rock, NC | United States |
| Age 0 to 4 | 3.1% | 2.1% | 5.9% |
| Age 5 to 9 | 4.6% | 2.9% | 6.1% |
| Age 10 to 14 | 6.2% | 4.1% | 6.6% |
| Age 15 to 17 | 3.3% | 0.8% | 3.9% |
| Age 18 to 20 | 3.7% | 1.4% | 4.0% |
| Age 21 to 24 | 3.7% | 1.6% | 5.2% |
| Age 25 to 34 | 5.9% | 5.1% | 13.8% |
| Age 35 to 44 | 6.6% | 6.3% | 12.9% |
| Age 45 to 54 | 12.2% | 9.0% | 12.6% |
| Age 55 to 59 | 10.0% | 9.4% | 6.7% |
| Age 60 to 64 | 8.0% | 8.7% | 6.3% |
| Age 65 to 74 | 15.1% | 27.6% | 9.6% |
| Age 75 to 84 | 7.8% | 17.7% | 4.5% |
| Age 85 and over | 9.9% | 3.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lake Barrington, IL | Flat Rock, NC | United States |
| White | 91.0% | 94.3% | 59.4% |
| Black | 0.2% | 0.0% | 12.2% |
| Asian | 2.8% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.8% | 0.0% | 0.4% |
| Two or More Races | 3.2% | 0.5% | 3.2% |
| Hispanic | 2.0% | 5.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lake Barrington, IL | Flat Rock, NC | United States |
| Married Population | 57.3% | 72.9% | 49.8% |
| Currently Married | 57.1% | 70.8% | 48.0% |
| Married but Separated | 0.2% | 2.2% | 1.8% |
| Single Population | 42.7% | 27.1% | 50.2% |
| Never Married | 18.7% | 11.6% | 33.8% |
| Divorced | 14.4% | 10.6% | 10.8% |
| Widowed | 9.5% | 5.0% | 5.6% |
| space5 | | | |
| Household Size | 2.25 | 2.07 | 2.60 |
| Households | 2,459 | 1,672 | 124,010,992 |
| Family Households | 1,507 | 1,140 | 80,755,759 |
| Married couple, w/children | 27.2% | 10.9% | 30.5% |
| Married couple, no children | 61.6% | 85.8% | 42.9% |
| Non Family Households | 952 | 532 | 43,255,233 |
| Single householder, w/children | 7.7% | 0.6% | 15.8% |
| Single householder, no children | 3.5% | 2.7% | 10.8% |