| Value | Category | Cases | |
|---|---|---|---|
| 1 | a.No difficulty | 2095 |
9.1%
|
| 2 | b.Some difficulty | 79 |
0.3%
|
| 3 | c.A lot of difficulty | 30 |
0.1%
|
| 4 | d.Cannot do at all | 3 |
0%
|
| Missing value | 20931 |
90.5%
|