| Value | Category | Cases | |
|---|---|---|---|
| 1 | a.No difficulty | 2145 |
9.3%
|
| 2 | b.Some difficulty | 24 |
0.1%
|
| 3 | c.A lot of difficulty | 8 |
0%
|
| 4 | d.Cannot do at all | 4 |
0%
|
| Missing value | 20957 |
90.6%
|