| Value | Category | Cases | |
|---|---|---|---|
| 1 | No difficulty | 4706 |
57.1%
|
| 2 | Minor difficult | 462 |
5.6%
|
| 3 | Big difficulty | 682 |
8.3%
|
| 8 | NA | 2372 | |
| 9 | I don’t know | 5 | |
| Sysmiss | 17 |