| Value | Category | Cases | |
|---|---|---|---|
| 1 | No-no difficulty | 66165 |
98.6%
|
| 2 | Yes-some difficulty | 518 |
0.8%
|
| 3 | Yes- a lot of difficulty | 243 |
0.4%
|
| 4 | can not do at all | 151 |
0.2%
|
| Sysmiss | 10684 |