| Value | Category | Cases | |
|---|---|---|---|
| 1 | No difficulty | 1520 |
15.3%
|
| 2 | Minor difficulty | 120 |
1.2%
|
| 3 | Big difficulty | 741 |
7.5%
|
| 8 | Not applicable | 5894 |
59.4%
|
| 9 | Don’t know | 1644 |
16.6%
|
| Sysmiss | 7 |