| Knox | Rock | |||||||||
| Illinois | County | Galesburg | Danville | Freeport | Moline | Normal | Pekin | Quincy | Island | |
| Population | 12,419,293 | 55,836 | 33,708 | 33,904 | 26,443 | 43,768 | 45,386 | 33,857 | 40,366 | 39,684 |
| Under 18 | 3,245,451 | 12,306 | 7,128 | 8,430 | 6,474 | 10,526 | 7,939 | 7,862 | 9,428 | 9,119 |
| 18 & up | 9,173,842 | 43,530 | 26,580 | 25,474 | 19,969 | 33,242 | 37,447 | 25,995 | 30,938 | 30,565 |
| 65 & up | 1,500,025 | 9,780 | 6,093 | 5,642 | 4,781 | 6,742 | 3,457 | 5,303 | 8,023 | 6,470 |
| Median Age | 34.7 | 39.4 | 38.1 | 36.6 | 37.9 | 37.9 | 23 | 37.1 | 38.4 | 36.4 |
| Black or African American (%) | 15.1 | 6.3 | 10.2 | 24.4 | 13.8 | 3.1 | 7.7 | 2.5 | 4.7 | 17.2 |
| Native American (%) | 0.2 | 0.2 | 0.2 | 0.5 | 0.2 | 0.2 | 0.1 | 0.4 | 0.2 | 0.3 |
| Asian (%) | 3.4 | 0.7 | 1.0 | 1.2 | 1.0 | 1.4 | 2.2 | 0.4 | 0.5 | 0.8 |
| Hispanic (%) | 12.3 | 3.4 | 5.0 | 4.6 | 2.1 | 11.9 | 2.6 | 1.3 | 0.9 | 5.9 |
| Total Households | 4,591,779 | 22,056 | 13,237 | 13,327 | 11,222 | 18,492 | 15,157 | 13,380 | 16,546 | 16,148 |
| Family Households (%) | 67.6 | 65.4 | 59.7 | 61.2 | 61.0 | 62.7 | 54.0 | 65.8 | 61.1 | 59.1 |
| Non-family Households (%) | 32.4 | 34.6 | 40.3 | 38.8 | 39.0 | 37.3 | 46.0 | 34.2 | 38.9 | 40.9 |
| Living Alone (%) | 26.8 | 29.6 | 34.6 | 33.9 | 33.7 | 31.9 | 26.6 | 29.5 | 33.7 | 34.5 |
| Households with Children under 18 (%) | 36.2 | 30.3 | 28.9 | 31.9 | 30.7 | 31.0 | 28.4 | 33.7 | 30.9 | 29.7 |
| Households including 65+ (%) | 23.2 | 30.0 | 31.3 | 30.4 | 29.2 | 26.4 | 14.9 | 27.4 | 30.0 | 28.3 |
| Average Household size | 2.63 | 2.33 | 2.24 | 2.35 | 2.29 | 2.35 | 2.43 | 2.37 | 2.30 | 2.31 |
| Average Family size | 3.23 | 2.87 | 2.87 | 3.01 | 2.93 | 2.97 | 2.96 | 2.92 | 2.94 | 2.97 |
| Owner-occupied households (%) | 67.3 | 71.6 | 64.3 | 62.5 | 68.2 | 67.3 | 55.2 | 67.2 | 66.4 | 65.1 |
| Renter-occupied households (%) | 32.7 | 28.4 | 35.7 | 37.5 | 31.8 | 32.7 | 44.8 | 32.8 | 33.6 | 34.9 |
| School Enrollment | 3,450,604 | 13,125 | 8,108 | 7,982 | 6,682 | 10,679 | 23,318 | 7,863 | 10,358 | 11,337 |
| Nursery/Preschool (%) | 7.3 | 5.9 | 6.2 | 7.2 | 8.5 | 6.9 | 2.5 | 8.2 | 7.9 | 7.1 |
| Kindergarten (%) | 5.5 | 4.4 | 4.4 | 6.4 | 7.0 | 5.1 | 1.8 | 5.4 | 4.8 | 4.3 |
| Grades 1-8 (%) | 43.2 | 43.4 | 39.3 | 46.2 | 42.7 | 43.1 | 15.4 | 44.0 | 42.4 | 37.8 |
| High School (%) | 20.5 | 21.8 | 20.6 | 23.8 | 20.3 | 24.5 | 7.1 | 24.0 | 22.2 | 18.0 |
| College or graduate school (%) | 23.5 | 24.4 | 29.5 | 16.5 | 21.5 | 20.4 | 73.2 | 18.3 | 22.7 | 32.8 |
| High School Graduates (%) | 81.4 | 81.8 | 79.2 | 75.2 | 82.2 | 84.1 | 93.9 | 81.6 | 82.7 | 82.9 |
| College Graduates (%) | 26.1 | 14.6 | 14.9 | 15.7 | 17.1 | 20.8 | 42.4 | 13.4 | 19.3 | 18.7 |
| Median household income 1999 | $46,590 | $35,407 | $31,987 | $30,431 | $35,399 | $39,363 | $40,379 | $37,972 | $30,956 | $34,729 |
| Median family income 1999 | $55,545 | $44,010 | $41,796 | $39,308 | $43,787 | $48,207 | $60,644 | $46,346 | $40,718 | $45,127 |
| Per capita income 1999 | $23,104 | $17,985 | $17,214 | $16,476 | $18,680 | $21,557 | $17,775 | $19,616 | $17,474 | $19,202 |
| Families in poverty (%) | 7.8 | 7.7 | 10.7 | 13.4 | 9.9 | 7.1 | 5.6 | 6.8 | 9.2 | 10.9 |
| Families in poverty with Children (%) | 11.6 | 14.0 | 19.6 | 21.3 | 16.2 | 12.3 | 8.3 | 10.7 | 14.8 | 19.1 |
| Individuals in poverty (%) | 10.7 | 11.1 | 14.7 | 18.1 | 13.1 | 9.5 | 19.3 | 9.4 | 12.2 | 14.5 |
| Total Housing Units | 4,885,615 | 23,717 | 14,115 | 14,686 | 12,479 | 19,495 | 15,636 | 14,002 | 17,995 | 17,507 |
| Single-unit (%) | 62.8 | 77.8 | 70.0 | 73.0 | 65.5 | 71.5 | 55.1 | 77.5 | 70.6 | 70.5 |
| 2 units (%) | 6.9 | 5.2 | 7.3 | 4.7 | 8.5 | 6.8 | 2.4 | 3.1 | 8.8 | 7.2 |
| 3 or 4 units (%) | 6.5 | 3.4 | 4.8 | 4.6 | 7.8 | 4.6 | 7.3 | 4.3 | 7.0 | 5.1 |
| 5 to 9 units (%) | 6.2 | 2.8 | 4.0 | 5.9 | 5.2 | 5.1 | 11.4 | 6.2 | 4.5 | 4.0 |
| 10 to 19 units (%) | 4.3 | 2.2 | 3.4 | 3.2 | 1.7 | 4.2 | 12.5 | 3.5 | 2.2 | 3.9 |
| 20 or more units (%) | 10.1 | 4.2 | 6.6 | 6.4 | 4.9 | 6.3 | 7.5 | 4.7 | 3.6 | 7.9 |
| Mobile homes (%) | 3.2 | 4.3 | 3.9 | 2.2 | 6.4 | 1.5 | 3.7 | 0.7 | 3.3 | 1.3 |
| other (%) | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.1 |
| Structures built since 1990 | 604,961 | 1,234 | 591 | 404 | 1,189 | 757 | 4,179 | 666 | 1,207 | 325 |
| Structures built 1980-1989 | 473,462 | 1,167 | 628 | 718 | 825 | 1,041 | 2,287 | 730 | 738 | 807 |
| Structures built 1970-1979 | 798,295 | 4,529 | 2,215 | 1,892 | 1,429 | 2,521 | 4,236 | 2,608 | 2,037 | 1,693 |
| Structures built 1960-1969 | 715,007 | 2,509 | 1,431 | 2,071 | 1,486 | 2,955 | 2,188 | 2,613 | 2,178 | 2,491 |
| Structures built 1940-1959 | 1,190,514 | 4,996 | 3,606 | 4,520 | 2,705 | 6,013 | 1,835 | 4,523 | 4,843 | 6,265 |
| Structures built before 1940 | 1,103,376 | 9,282 | 5,644 | 5,081 | 4,845 | 6,208 | 911 | 2,862 | 6,992 | 5,926 |