| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 2431 |
87%
|
| 2 | SOME DIFFICULTY | 281 |
10.1%
|
| 3 | A LOT OF DIFFICULTY | 20 |
0.7%
|
| 4 | CANNOT SEE AT ALL | 7 |
0.3%
|
| Sysmiss | 55 |
2%
|