| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 3026 |
64.7%
|
| 2 | SOME DIFFICULTY | 375 |
8%
|
| 3 | A LOT OF DIFFICULTY | 40 |
0.9%
|
| 4 | CANNOT SEE AT ALL | 1 |
0%
|
| Sysmiss | 1235 |
26.4%
|