| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
16.7%
|
| 1972 | 1 |
5.6%
|
|
| 1974 | 1 |
5.6%
|
|
| 1993 | 2 |
11.1%
|
|
| 1994 | 1 |
5.6%
|
|
| 1995 | 2 |
11.1%
|
|
| 1997 | 1 |
5.6%
|
|
| 2000 | 3 |
16.7%
|
|
| 2008 | 1 |
5.6%
|
|
| 2014 | 1 |
5.6%
|
|
| 2015 | 1 |
5.6%
|
|
| 2022 | 1 |
5.6%
|
|
| Sysmiss | 85 |