| Value | Category | Cases | |
|---|---|---|---|
| 1 | No difficulty | 1590 |
72.1%
|
| 2 | Minor difficult | 93 |
4.2%
|
| 3 | Big difficulty | 95 |
4.3%
|
| 8 | NA | 416 |
18.9%
|
| 9 | I don’t know | 6 |
0.3%
|
| Sysmiss | 4 |