| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 0 |
0%
|
| 0 | Never | 128 |
10.1%
|
| 1 | Once or twice | 149 |
11.8%
|
| 2 | Several times | 78 |
6.2%
|
| 3 | Many times | 14 |
1.1%
|
| 7 | Not applicable/Saw no problems | 886 |
70.1%
|
| 9 | Don't know | 9 |
0.7%
|
| 998 | Refused | 0 |
0%
|