| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 1976 |
73.9%
|
| 2 | SOME DIFFICULTY | 245 |
9.2%
|
| 3 | A LOT OF DIFFICULTY | 20 |
0.7%
|
| 4 | CANNOT SEE AT ALL | 2 |
0.1%
|
| Sysmiss | 430 |
16.1%
|