| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
3.7%
|
| 1995 | 1 |
0.9%
|
|
| 2011 | 1 |
0.9%
|
|
| 2012 | 2 |
1.9%
|
|
| 2014 | 3 |
2.8%
|
|
| 2015 | 7 |
6.5%
|
|
| 2016 | 13 |
12.1%
|
|
| 2017 | 21 |
19.6%
|
|
| 2018 | 47 |
43.9%
|
|
| 2019 | 8 |
7.5%
|
|
| Sysmiss | 253 |