| Value | Category | Cases | |
|---|---|---|---|
| -1 | missing | 0 |
0%
|
| 1 | very easy | 948 |
2%
|
| 2 | easy | 2294 |
4.8%
|
| 3 | difficult | 2119 |
4.4%
|
| 4 | very difficult | 1491 |
3.1%
|
| 7 | not applicable | 41215 |
85.7%
|
| 8 | refused | 1 |
0%
|
| 9 | don't know | 16 |
0%
|