| Value | Category | Cases | |
|---|---|---|---|
| 0 | No | 21861 |
94.2%
|
| 1 | Yes, once | 660 |
2.8%
|
| 2 | Yes, more than once | 677 |
2.9%
|
| 9 | Missing | 554 | |
| Sysmiss | 10844 |