| Value | Category | Cases | |
|---|---|---|---|
| 1 | a.No difficulty | 13172 |
82.3%
|
| 2 | b.Some difficulty | 467 |
2.9%
|
| 3 | c.A lot of difficulty | 133 |
0.8%
|
| 4 | d.Cannot do at all | 50 |
0.3%
|
| Missing value | 2184 |
13.6%
|