| Value | Category | Cases | |
|---|---|---|---|
| -99 | NA | 3526 |
75.4%
|
| -97 | Refused | 91 |
1.9%
|
| 1 | Very difficult | 248 |
5.3%
|
| 2 | Fairly difficult | 179 |
3.8%
|
| 3 | Fairly easy | 254 |
5.4%
|
| 4 | Very easy | 377 |
8.1%
|