| Code | Definition | Number of Accessions |
| 1 | very narrow < 1,0 cm | 54 |
| 2 | very narrow - narrow 1,0 -1,2 cm | 330 |
| 3 | narrow 1,3 -1,2 cm | 1383 |
| 4 | narrow - medium 1,6 -1,7 cm | 804 |
| 5 | medium 1,8 -2,0 cm | 487 |
| 6 | medium - broad 2,1 -2,2 cm | 159 |
| 7 | broad 2,3 -2,5 cm | 123 |
| 8 | broad - very broad 2,6 -2,8 cm | 16 |
| 9 | very broad >2,8 cm | 3 |