| Code | Definition | Number of Accessions |
| 1 | very low < 18,0 (g.kg-1) | 8 |
| 2 | very low to low 18,0 - 21,0 (g.kg-1) | 11 |
| 3 | low 21,1 - 24,0 (g.kg-1) | 9 |
| 4 | low to intermediate 24,1 - 27,0 (g.kg-1) | 8 |
| 5 | intermediate 27,1 - 30,0 (g.kg-1) | 2 |
| 6 | intermediate to high 30,1 - 33,0 (g.kg-1) | 2 |
| 7 | high 33,1 - 36,0 (g.kg-1) | 4 |
| 9 | very high > 39,0 (g.kg-1) | 1 |