| Value | Category | Cases | |
|---|---|---|---|
| 1 | No-no difficulty | 63413 |
94.5%
|
| 2 | Yes-some difficulty | 3030 |
4.5%
|
| 3 | Yes- a lot of difficulty | 594 |
0.9%
|
| 4 | can not do at all | 40 |
0.1%
|
| Sysmiss | 10684 |