| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1. higher grade | 0 |
0%
|
| 2 | 2. standard grade | 1 |
1.3%
|
| 3 | 3. lower grade | 0 |
0%
|
| 7 | 7. did not take | 23 |
30.7%
|
| 9 | 9. don't know | 51 |
68%
|
| Sysmiss | 924 |