Illinois Gazetteer
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. | Cook County | 83.2 |
| 2. | Kane County | 78.2 |
| 3. | Lake County | 75.2 |
| 4. | Will County | 70.8 |
| 5. | Kendall County | 68.0 |
| 6. | DuPage County | 66.8 |
| 7. | Boone County | 66.4 |
| 8. | Winnebago County | 65.1 |
| 9. | Cass County | 64.6 |
| 10. | Champaign County | 64.4 |
| 11. | Rock Island County | 60.9 |
| 12. | St. Clair County | 60.1 |
| 13. | Kankakee County | 59.0 |
| 14. | DeKalb County | 58.2 |
| 15. | Pulaski County | 56.8 |
| 16. | Peoria County | 56.7 |
| 17. | Alexander County | 53.7 |
| 18. | McHenry County | 53.2 |
| 19. | Jackson County | 52.2 |
| 20. | McLean County | 47.2 |
