| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 3870 |
59.7%
|
| 2 | SOME DIFFICULTY | 774 |
11.9%
|
| 3 | A LOT OF DIFFICULTY | 98 |
1.5%
|
| 4 | CANNOT SEE AT ALL | 1 |
0%
|
| 9 | NO RESPONSE | 7 |
0.1%
|
| Sysmiss | 1733 |
26.7%
|