| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 10 |
0.8%
|
| 0 | Never | 648 |
54%
|
| 1 | Once or twice | 47 |
3.9%
|
| 2 | Several times | 20 |
1.7%
|
| 3 | Many times | 2 |
0.2%
|
| 7 | Not applicable/Saw no problems | 469 |
39.1%
|
| 9 | Don't know | 4 |
0.3%
|