| Value | Category | Cases | |
|---|---|---|---|
| 1 | No | 1960 |
98.6%
|
| 2 | Once | 16 |
0.8%
|
| 3 | More than once | 2 |
0.1%
|
| 4 | Not applicable | 7 |
0.4%
|
| Sysmiss | 3 |