| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
20.8%
|
| 2002 | 1 |
4.2%
|
|
| 2012 | 1 |
4.2%
|
|
| 2015 | 1 |
4.2%
|
|
| 2018 | 2 |
8.3%
|
|
| 2019 | 3 |
12.5%
|
|
| 2020 | 3 |
12.5%
|
|
| 2021 | 6 |
25%
|
|
| 2022 | 2 |
8.3%
|
|
| Sysmiss | 1276 |