(Links below lead to Quick Facts for Arizona Counties: People, Business & Geography at U.S. Census Bureau.)
| Area | 7/1/2009 | 7/1/2008 | 7/1/2007 | 7/1/2006 | 7/1/2005 | 7/1/2004 | 7/1/2003 | 7/1/2002 | 7/1/2001 | 7/1/2000 | Census 2000 |
| Arizona | 6,595,778 | 6,499,377 | 6,362,241 | 6,192,100 | 5,974,834 | 5,759,425 | 5,591,206 | 5,452,108 | 5,304,417 | 5,166,697 | 5,130,632 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Apache County | 70,591 | 69,520 | 69,278 | 69,066 | 68,250 | 67,943 | 67,938 | 67,267 | 67,857 | 69,516 | 69,423 |
| Cochise County | 129,518 | 128,425 | 127,736 | 126,751 | 125,637 | 123,235 | 121,175 | 119,750 | 118,573 | 118,028 | 117,755 |
| Coconino County | 129,849 | 128,426 | 127,451 | 126,029 | 124,804 | 123,349 | 121,545 | 120,390 | 117,803 | 116,717 | 116,320 |
| Gila County | 52,199 | 52,273 | 52,231 | 51,635 | 50,914 | 50,848 | 50,906 | 51,225 | 51,165 | 51,355 | 51,335 |
| Graham County | 37,045 | 36,204 | 34,736 | 33,286 | 32,629 | 32,441 | 32,785 | 33,120 | 33,307 | 33,541 | 33,489 |
| Greenlee County | 8,041 | 8,058 | 7,760 | 7,465 | 7,292 | 7,307 | 7,381 | 7,706 | 8,281 | 8,542 | 8,547 |
| La Paz County | 20,012 | 20,005 | 20,133 | 20,118 | 20,007 | 19,696 | 19,516 | 19,346 | 19,537 | 19,643 | 19,715 |
| Maricopa County | 4,023,132 | 3,958,263 | 3,872,962 | 3,776,118 | 3,647,131 | 3,502,635 | 3,391,391 | 3,299,127 | 3,200,075 | 3,097,378 | 3,072,149 |
| Mohave County | 194,825 | 195,601 | 195,852 | 192,724 | 185,940 | 178,313 | 171,019 | 165,177 | 159,840 | 156,194 | 155,032 |
| Navajo County | 112,975 | 112,348 | 110,999 | 109,000 | 106,968 | 105,020 | 103,220 | 101,358 | 98,549 | 97,876 | 97,470 |
| Pima County | 1,020,200 | 1,009,832 | 996,593 | 975,476 | 948,965 | 924,205 | 903,320 | 886,063 | 865,694 | 848,521 | 843,746 |
| Pinal County | 340,962 | 329,060 | 302,633 | 270,453 | 237,457 | 220,724 | 208,772 | 197,830 | 188,370 | 181,283 | 179,727 |
| Santa Cruz County | 43,771 | 43,133 | 42,692 | 42,040 | 41,113 | 40,177 | 39,541 | 39,288 | 38,914 | 38,542 | 38,381 |
| Yavapai County | 215,686 | 214,930 | 212,004 | 206,672 | 197,533 | 189,532 | 183,400 | 178,390 | 173,285 | 168,886 | 167,517 |
| Yuma County | 196,972 | 193,299 | 189,181 | 185,267 | 180,194 | 174,000 | 169,297 | 166,071 | 163,167 | 160,675 | 160,026 |
Source: Population Division, U.S. Census Bureau