| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 3649 |
57.7%
|
| 2 | SOME DIFFICULTY | 50 |
0.8%
|
| 3 | A LOT OF DIFFICULTY | 6 |
0.1%
|
| 4 | CANNOT SEE AT ALL | 3 |
0%
|
| 9 | NO RESPONSE | 8 |
0.1%
|
| Sysmiss | 2612 |