| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 2564 |
91.8%
|
| 2 | SOME DIFFICULTY | 159 |
5.7%
|
| 3 | A LOT OF DIFFICULTY | 12 |
0.4%
|
| 4 | CANNOT SEE AT ALL | 4 |
0.1%
|
| Sysmiss | 55 |
2%
|