| Value | Category | Cases | |
|---|---|---|---|
| 0 | Never | 3560 |
99.7%
|
| 1 | Once or twice | 9 |
0.3%
|
| 2 | Several times | 0 |
0%
|
| 3 | Many times | 0 |
0%
|
| 8 | Refused | 0 |
0%
|
| 9 | Missing | 3 |
0.1%
|
| Sysmiss | 47 |