| Value | Category | Cases | |
|---|---|---|---|
| 1 | a.No difficulty | 38 |
0.2%
|
| 2 | b.Some difficulty | 27 |
0.1%
|
| 3 | c.A lot of difficulty | 16 |
0.1%
|
| 4 | d.Cannot do at all | 17 |
0.1%
|
| Missing value | 23040 |
99.6%
|