| Value | Category | Cases | |
|---|---|---|---|
| -1 | missing | 0 |
0%
|
| 1 | very easy | 2848 |
5.9%
|
| 2 | easy | 6785 |
14.1%
|
| 3 | difficult | 4544 |
9.5%
|
| 4 | very difficult | 3836 |
8%
|
| 7 | not applicable | 30044 |
62.5%
|
| 8 | refused | 1 |
0%
|
| 9 | don't know | 26 |
0.1%
|