The Diversity Index is a scale of 0 to 100 that represents the likelyhood that two persons, chosen at random from the same area, belong to different race or ethnic groups. If an area's entire population belongs to one race AND one ethnic group, then the area has zero diversity. An area's diversity index increases to 100 when the population is evenly divided into two or more race/ethnic groups.
| County | Diversity Index | |
|---|---|---|
| 1. | Yuma County | 75.3 |
| 2. | La Paz County | 74.6 |
| 3. | Pima County | 73.0 |
| 4. | Maricopa County | 72.8 |
| 5. | Greenlee County | 71.9 |
| 6. | Pinal County | 71.1 |
| 7. | Graham County | 70.4 |
| 8. | Cochise County | 68.7 |
| 9. | Coconino County | 67.1 |
| 10. | Navajo County | 66.7 |
| 11. | Santa Cruz County | 62.6 |
| 12. | Gila County | 61.7 |
| 13. | Mohave County | 49.2 |
| 14. | Apache County | 47.9 |
| 15. | Yavapai County | 42.8 |
