| Source and Type | Number Identified & Screened | Number Retained | Percent Retained |
|---|---|---|---|
| National Climatic Data Center | |||
| Digitized | 1171 | 922 | 79% |
| Summarized | 1252 | 840 | 67% |
| Unsummarized | 1593 | 461 | 29% |
| Forest Service | 1727 | 227 | 13% |
| Nuclear and Fossil-Fuel Power Plant | 151 | 128 | 85% |
| Foreign (Peripheral Areas) | 149 | 136 | 91% |
| Other | 676 | 483 | 71% |
| Total | 6719 | 3197 | 48% |