| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 1943 |
54.6%
|
| 2 | SOME DIFFICULTY | 87 |
2.4%
|
| 3 | A LOT OF DIFFICULTY | 19 |
0.5%
|
| 4 | CANNOT SEE AT ALL | 1 |
0%
|
| 9 | NO RESPONSE | 2 |
0.1%
|
| Sysmiss | 1508 |
42.4%
|