| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 1 |
0.1%
|
| 0 | Never | 324 |
29.3%
|
| 1 | Once or twice | 187 |
16.9%
|
| 2 | Several times | 137 |
12.4%
|
| 3 | Many times | 30 |
2.7%
|
| 7 | Not applicable/Saw no problems | 418 |
37.9%
|
| 9 | Don't know | 7 |
0.6%
|
| 998 | Refused | 0 |
0%
|