| Value | Category | Cases | |
|---|---|---|---|
| 1 | a.No difficulty | 1303 |
8.1%
|
| 2 | b.Some difficulty | 54 |
0.3%
|
| 3 | c.A lot of difficulty | 27 |
0.2%
|
| 4 | d.Cannot do at all | 4 |
0%
|
| Missing value | 14618 |
91.3%
|