| Value | Category | Cases | |
|---|---|---|---|
| 1 | a.No difficulty | 8155 |
35.2%
|
| 2 | b.Some difficulty | 171 |
0.7%
|
| 3 | c.A lot of difficulty | 39 |
0.2%
|
| 4 | d.Cannot do at all | 9 |
0%
|
| Missing value | 14764 |
63.8%
|