| Value | Category | Cases | |
|---|---|---|---|
| 1 | No-no difficulty | 60971 |
98.6%
|
| 2 | Yes-some difficulty | 602 |
1%
|
| 3 | Yes- a lot of difficulty | 205 |
0.3%
|
| 4 | can not do at all | 28 |
0%
|
| Sysmiss | 8618 |