| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 27 |
13.6%
|
| 2003 | 1 |
0.5%
|
|
| 2004 | 1 |
0.5%
|
|
| 2008 | 1 |
0.5%
|
|
| 2010 | 2 |
1%
|
|
| 2012 | 2 |
1%
|
|
| 2013 | 3 |
1.5%
|
|
| 2014 | 2 |
1%
|
|
| 2015 | 13 |
6.5%
|
|
| 2016 | 18 |
9%
|
|
| 2017 | 30 |
15.1%
|
|
| 2018 | 76 |
38.2%
|
|
| 2019 | 23 |
11.6%
|
|
| Sysmiss | 163 |