| Code | Definition | Number of Accessions |
| 1 | very low < 16,0 (g.kg-1) | 5 |
| 2 | very low to low 16,0 - 18,0 (g.kg-1) | 7 |
| 3 | low 18,1 - 20,0 (g.kg-1) | 7 |
| 4 | low to intermediate 20,1 - 22,0 (g.kg-1) | 8 |
| 5 | intermediate 22,1 - 24,0 (g.kg-1) | 7 |
| 6 | intermediate to high 24,1 - 26,0 (g.kg-1) | 5 |
| 7 | high 26,1 - 28,0 (g.kg-1) | 7 |
| 8 | high to very high 28,1 - 30,0 (g.kg-1) | 3 |
| 9 | very high > 30,0 (g.kg-1) | 5 |