| Value | Category | Cases | |
|---|---|---|---|
| 1 | a.No difficulty | 14626 |
91.4%
|
| 2 | b.Some difficulty | 446 |
2.8%
|
| 3 | c.A lot of difficulty | 120 |
0.7%
|
| 4 | d.Cannot do at all | 18 |
0.1%
|
| Missing value | 796 |
5%
|