| | Sigourney, IA | Gig Harbor, WA | United States |
| Population | 1,805 | 11,505 | 329,725,481 |
| Female Population | 47.3% | 53.9% | 50.5% |
| Male Population | 52.7% | 46.1% | 49.5% |
| Median Age | 49.4 | 41.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,059 | 7,124 | 309,327,143 |
| Population - 2000 | 2,209 | 6,465 | 285,036,114 |
| Population - 1990 | 2,111 | 3,236 | 251,960,433 |
| Pop. 2000 to Now | -10.4% | 68.2% | 15.6% |
| Pop. 1990 to Now | -6.2% | 236.0% | 30.8% |
| space4 | | | |
| Population Density | 826.8 | 1,949.7 | 93.4 |
| Land Area | 2.2 | 5.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Sigourney, IA | Gig Harbor, WA | United States |
| Age 0 to 4 | 2.3% | 7.1% | 5.9% |
| Age 5 to 9 | 3.4% | 6.6% | 6.1% |
| Age 10 to 14 | 6.8% | 7.5% | 6.6% |
| Age 15 to 17 | 3.6% | 3.1% | 3.9% |
| Age 18 to 20 | 4.5% | 4.0% | 4.0% |
| Age 21 to 24 | 2.0% | 3.7% | 5.2% |
| Age 25 to 34 | 11.0% | 10.0% | 13.8% |
| Age 35 to 44 | 11.9% | 10.9% | 12.9% |
| Age 45 to 54 | 12.1% | 9.9% | 12.6% |
| Age 55 to 59 | 6.5% | 6.0% | 6.7% |
| Age 60 to 64 | 5.0% | 5.9% | 6.3% |
| Age 65 to 74 | 12.8% | 12.4% | 9.6% |
| Age 75 to 84 | 12.1% | 8.3% | 4.5% |
| Age 85 and over | 6.1% | 4.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Sigourney, IA | Gig Harbor, WA | United States |
| White | 97.0% | 80.4% | 59.4% |
| Black | 0.9% | 0.4% | 12.2% |
| Asian | 0.1% | 4.5% | 5.6% |
| Native American | 0.0% | 0.7% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.3% | 0.2% |
| Other | 0.0% | 0.5% | 0.4% |
| Two or More Races | 1.7% | 6.1% | 3.2% |
| Hispanic | 0.4% | 7.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Sigourney, IA | Gig Harbor, WA | United States |
| Married Population | 44.0% | 62.2% | 49.8% |
| Currently Married | 43.2% | 61.1% | 48.0% |
| Married but Separated | 0.8% | 1.1% | 1.8% |
| Single Population | 56.0% | 37.8% | 50.2% |
| Never Married | 27.3% | 19.2% | 33.8% |
| Divorced | 16.5% | 10.1% | 10.8% |
| Widowed | 12.2% | 8.5% | 5.6% |
| space5 | | | |
| Household Size | 1.94 | 2.42 | 2.60 |
| Households | 876 | 4,672 | 124,010,992 |
| Family Households | 480 | 2,986 | 80,755,759 |
| Married couple, w/children | 15.6% | 38.1% | 30.5% |
| Married couple, no children | 53.8% | 50.3% | 42.9% |
| Non Family Households | 396 | 1,686 | 43,255,233 |
| Single householder, w/children | 21.5% | 7.7% | 15.8% |
| Single householder, no children | 9.2% | 3.8% | 10.8% |