| | Guernsey, WY | Centennial, CO | United States |
| Population | 1,016 | 107,972 | 329,725,481 |
| Female Population | 45.8% | 49.6% | 50.5% |
| Male Population | 54.2% | 50.4% | 49.5% |
| Median Age | 47.5 | 41.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,146 | 100,294 | 309,327,143 |
| Population - 2000 | 1,147 | 100,309 | 285,036,114 |
| Population - 1990 | 1,155 | 81,946 | 251,960,433 |
| Pop. 2000 to Now | -0.4% | 9.8% | 15.6% |
| Pop. 1990 to Now | -1.0% | 34.4% | 30.8% |
| space4 | | | |
| Population Density | 991.2 | 3,650.5 | 93.4 |
| Land Area | 1.0 | 29.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Guernsey, WY | Centennial, CO | United States |
| Age 0 to 4 | 8.8% | 5.4% | 5.9% |
| Age 5 to 9 | 9.2% | 6.5% | 6.1% |
| Age 10 to 14 | 5.5% | 7.4% | 6.6% |
| Age 15 to 17 | 3.7% | 4.1% | 3.9% |
| Age 18 to 20 | 0.4% | 2.8% | 4.0% |
| Age 21 to 24 | 1.7% | 3.5% | 5.2% |
| Age 25 to 34 | 10.7% | 11.3% | 13.8% |
| Age 35 to 44 | 7.9% | 14.8% | 12.9% |
| Age 45 to 54 | 9.8% | 13.6% | 12.6% |
| Age 55 to 59 | 8.9% | 7.0% | 6.7% |
| Age 60 to 64 | 6.7% | 7.2% | 6.3% |
| Age 65 to 74 | 13.3% | 10.2% | 9.6% |
| Age 75 to 84 | 10.1% | 4.3% | 4.5% |
| Age 85 and over | 3.3% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Guernsey, WY | Centennial, CO | United States |
| White | 90.0% | 78.0% | 59.4% |
| Black | 0.0% | 2.6% | 12.2% |
| Asian | 0.0% | 5.9% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 0.0% | 0.5% | 0.4% |
| Two or More Races | 7.8% | 3.6% | 3.2% |
| Hispanic | 2.3% | 9.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Guernsey, WY | Centennial, CO | United States |
| Married Population | 71.1% | 60.2% | 49.8% |
| Currently Married | 70.4% | 59.4% | 48.0% |
| Married but Separated | 0.6% | 0.7% | 1.8% |
| Single Population | 28.9% | 39.8% | 50.2% |
| Never Married | 13.6% | 25.1% | 33.8% |
| Divorced | 8.4% | 10.9% | 10.8% |
| Widowed | 6.9% | 3.8% | 5.6% |
| space5 | | | |
| Household Size | 2.36 | 2.63 | 2.60 |
| Households | 431 | 40,344 | 124,010,992 |
| Family Households | 287 | 29,979 | 80,755,759 |
| Married couple, w/children | 26.8% | 36.2% | 30.5% |
| Married couple, no children | 68.6% | 46.3% | 42.9% |
| Non Family Households | 144 | 10,365 | 43,255,233 |
| Single householder, w/children | 4.5% | 10.7% | 15.8% |
| Single householder, no children | 0.0% | 6.8% | 10.8% |