| Value | Category | Cases | |
|---|---|---|---|
| 1 | Very easy | 538 |
24.5%
|
| 2 | Easy | 675 |
30.7%
|
| 3 | Difficult | 553 |
25.2%
|
| 4 | Very difficult | 191 |
8.7%
|
| 9 | Don't know | 241 |
11%
|