| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1992 | 1 |
0.8%
|
|
| 1995 | 1 |
0.8%
|
|
| 1999 | 1 |
0.8%
|
|
| 2000 | 8 |
6.5%
|
|
| 2005 | 3 |
2.4%
|
|
| 2006 | 4 |
3.2%
|
|
| 2008 | 1 |
0.8%
|
|
| 2009 | 3 |
2.4%
|
|
| 2010 | 5 |
4%
|
|
| 2011 | 3 |
2.4%
|
|
| 2012 | 3 |
2.4%
|
|
| 2013 | 5 |
4%
|
|
| 2014 | 7 |
5.6%
|
|
| 2015 | 10 |
8.1%
|
|
| 2016 | 12 |
9.7%
|
|
| 2017 | 6 |
4.8%
|
|
| 2018 | 38 |
30.6%
|
|
| 2019 | 13 |
10.5%
|
|
| Sysmiss | 126 |