| Variable | No. | % |
| EHL grading | ||
| Grade 1 | 0 | - |
| Grade 2 | 0 | - |
| Grade 3 | 2 | 6.7 |
| Grade 4 | 11 | 36.7 |
| Grade 5 | 17 | 56.7 |
| Total | 30 | 100.0 |
| FHL grading | ||
| Grade 1 | 0 | - |
| Grade 2 | 0 | - |
| Grade 3 | 0 | - |
| Grade 4 | 13 | 43.3 |
| Grade 5 | 17 | 56.7 |
| Total | 30 | 100.0 |