| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 5102 |
59.9%
|
| 2 | SOME DIFFICULTY | 1126 |
13.2%
|
| 3 | A LOT OF DIFFICULTY | 220 |
2.6%
|
| 4 | CANNOT SEE AT ALL | 1 |
0%
|
| 9 | NO RESPONSE | 12 |
0.1%
|
| Sysmiss | 2050 |
24.1%
|