| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 |
11.1%
|
| 2000 | 1 |
1%
|
|
| 2008 | 1 |
1%
|
|
| 2015 | 2 |
2%
|
|
| 2017 | 2 |
2%
|
|
| 2018 | 5 |
5.1%
|
|
| 2019 | 3 |
3%
|
|
| 2020 | 15 |
15.2%
|
|
| 2021 | 26 |
26.3%
|
|
| 2022 | 23 |
23.2%
|
|
| 2023 | 10 |
10.1%
|
|
| Sysmiss | 501 |