| Value | Category | Cases | |
|---|---|---|---|
| -2 | No answer | 20 |
1.7%
|
| -1 | Don't know | 7 |
0.6%
|
| 1 | Lower | 788 |
65.7%
|
| 2 | Middle | 222 |
18.5%
|
| 3 | Higher | 163 |
13.6%
|