| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 1 |
0.1%
|
| 0 | Never | 366 |
30.5%
|
| 1 | Once or twice | 113 |
9.4%
|
| 2 | Several times | 170 |
14.2%
|
| 3 | Many times | 54 |
4.5%
|
| 7 | Not applicable/Saw no problems | 491 |
40.9%
|
| 9 | Don't know | 5 |
0.4%
|
| 998 | Refused | 0 |
0%
|