| |
Date |
Group |
| Cluster 1 |
May 26, 2007 |
Arizona, Washington, Eastern North Dakota |
| Cluster 2 |
July 19, 2007 |
California, New Mexico and Texas |
| Cluster 3 |
August 23, 2007 |
Michigan, New York |
| Cluster 4 |
October 12, 2007 |
Vermont, North Dakota (remainder) |
| Cluster 5 |
November 5, 2007 |
Idaho, Montana |
| Cluster 6 |
TBD |
Maine, Minnesota |
| Cluster 7 |
TBD |
Alaska |
