| Code | Definition | Number of Accessions |
| 1 | HIGHEST | 24 |
| 2 | (1 = HIGHEST, 9 = LOWEST) | 99 |
| 3 | (1 = HIGHEST, 9 = LOWEST) | 327 |
| 4 | (1 = HIGHEST, 9 = LOWEST) | 654 |
| 5 | (1 = HIGHEST, 9 = LOWEST) | 974 |
| 6 | (1 = HIGHEST, 9 = LOWEST) | 647 |
| 7 | (1 = HIGHEST, 9 = LOWEST) | 424 |
| 8 | (1 = HIGHEST, 9 = LOWEST) | 203 |
| 9 | LOWEST | 53 |