| Value | Category | Cases | |
|---|---|---|---|
| 0 | No | 2191 |
97.6%
|
| 1 | Yes, once | 41 |
1.8%
|
| 2 | Yes, more than once | 14 |
0.6%
|
| 9 | 37 | ||
| Sysmiss | 2982 |