| Value | Category | Cases | |
|---|---|---|---|
| -1 | missing | 0 |
0%
|
| 1 | very easy | 4846 |
9.1%
|
| 2 | easy | 12121 |
22.7%
|
| 3 | difficult | 8532 |
16%
|
| 4 | very difficult | 5315 |
9.9%
|
| 7 | not applicable | 22614 |
42.3%
|
| 8 | refused | 2 |
0%
|
| 9 | don't know | 14 |
0%
|