| Value | Category | Cases | |
|---|---|---|---|
| -2 | No answer | 8 |
0.6%
|
| -1 | Don't know | 3 |
0.2%
|
| 1 | Lower | 137 |
10.6%
|
| 2 | Middle | 294 |
22.8%
|
| 3 | Higher | 847 |
65.7%
|