| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 |
7.7%
|
| 2001 | 1 |
0.5%
|
|
| 2007 | 1 |
0.5%
|
|
| 2013 | 2 |
1.1%
|
|
| 2015 | 4 |
2.2%
|
|
| 2016 | 1 |
0.5%
|
|
| 2017 | 3 |
1.6%
|
|
| 2018 | 7 |
3.8%
|
|
| 2019 | 5 |
2.7%
|
|
| 2020 | 20 |
10.9%
|
|
| 2021 | 32 |
17.5%
|
|
| 2022 | 61 |
33.3%
|
|
| 2023 | 32 |
17.5%
|
|
| Sysmiss | 168 |