| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 3285 |
81.3%
|
| 2 | SOME DIFFICULTY | 660 |
16.3%
|
| 3 | A LOT OF DIFFICULTY | 97 |
2.4%
|
| 4 | CANNOT SEE AT ALL | 1 |
0%
|
| 9 | NO RESPONSE | 0 |
0%
|
| Sysmiss | 1470 |