| Code | Definition | Number of Accessions |
| 1 | SINGLE | 601 |
| 2 | (1 = SINGLE, 9 = MULTIPLE) | 48 |
| 3 | (1 = SINGLE, 9 = MULTIPLE) | 347 |
| 4 | (1 = SINGLE, 9 = MULTIPLE) | 8 |
| 5 | (1 = SINGLE, 9 = MULTIPLE) | 407 |
| 6 | (1 = SINGLE, 9 = MULTIPLE) | 2 |
| 7 | (1 = SINGLE, 9 = MULTIPLE) | 361 |
| 8 | (1 = SINGLE, 9 = MULTIPLE) | 2 |
| 9 | MULTIPLE | 546 |
| M | MIXED | 140 |