Table 4.
Grade 6 | Grade 7 | Grade 8 | Percentage (%) |
---|---|---|---|
High | High | High | 16 |
High | High | Low | 1 |
High | Low | High | 2 |
High | Low | Low | 6 |
Low | High | High | 3 |
Low | High | Low | 0 |
Low | Low | High | 9 |
Low | Low | Low | 62 |
Low low exposure class. High high exposure class