| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 2127 |
76.1%
|
| 2 | SOME DIFFICULTY | 579 |
20.7%
|
| 3 | A LOT OF DIFFICULTY | 29 |
1%
|
| 4 | CANNOT SEE AT ALL | 3 |
0.1%
|
| 9 | NO RESPONSE | 1 |
0%
|
| Sysmiss | 55 |
2%
|