| Atlas Volume | Region | Identified & Screened | Retained | Percent Retained |
|---|---|---|---|---|
| 1 | Northwest | 1272 | 463 | 36% |
| 2 | North Central | 369 | 212 | 57% |
| 3 | Great Lakes | 534 | 304 | 57% |
| 4 | Northeast | 798 | 377 | 47% |
| 5 | East Central | 488 | 224 | 46% |
| 6 | Southeast | 495 | 185 | 37% |
| 7 | South Central | 415 | 269 | 65% |
| 8 | Southern Rocky Mountain | 701 | 363 | 52% |
| 9 | Southwest | 961 | 358 | 37% |
| 10 | Alaska | 535 | 326 | 61% |
| 11 | Hawaii & Pacific Islands | 131 | 96 | 73% |
| 12 | Puerto Rico & U.S. Virgin Islands | 20 | 20 | 100% |
| Total | 6719 | 3197 | 48% |