| Value | Category | Cases | |
|---|---|---|---|
| 1 | Probably induced | 552 |
13.8%
|
| 2 | Possibly induced | 478 |
11.9%
|
| 3 | Most likely spontaneous | 2831 |
70.7%
|
| 98 | Don't know | 127 |
3.2%
|
| 99 | Refused | 14 |
0.3%
|
| Sysmiss | 143 |