| Code | Definition | Number of Accessions |
| 1 | very low <10,0 (g.kg-1) | 4 |
| 2 | very low to low 10,0-13,0 (g.kg-1) | 4 |
| 3 | low 13,1-16,0 (g.kg-1) | 4 |
| 4 | low to medium 16,1-19,0 (g.kg-1) | 5 |
| 5 | medium 19,1-22,0 (g.kg-1) | 4 |
| 6 | medium to high 22,1-25,0 (g.kg-1) | 4 |
| 7 | high 25,1-28,0 (g.kg-1) | 3 |