| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not difficult at all | 628 |
10.9%
|
| 2 | Somewhat difficult | 951 |
16.5%
|
| 3 | Very difficult | 3166 |
54.8%
|
| 4 | Impossible | 1030 |
17.8%
|