| Value | Category | Cases | |
|---|---|---|---|
| -1 | missing | 0 |
0%
|
| 1 | very easy | 2685 |
5%
|
| 2 | easy | 6053 |
11.3%
|
| 3 | difficult | 4313 |
8.1%
|
| 4 | very difficult | 4004 |
7.5%
|
| 7 | not applicable | 36369 |
68.1%
|
| 8 | refused | 1 |
0%
|
| 9 | don't know | 19 |
0%
|