| Region | number of states |
|---|---|
| Northeast | 9 |
| Midwest | 12 |
| South | 17 |
| West | 13 |
| Region | Division | number of states |
|---|---|---|
| Northeast | New England | 6 |
| Northeast | Mid-Atlantic | 3 |
| Midwest | East North Central | 5 |
| Midwest | West North Central | 7 |
| South | South Atlantic | 9 |
| South | East South Central | 4 |
| South | West South Central | 4 |
| West | Mountain | 8 |
| West | Pacific | 5 |
