| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
8.3%
|
| 2005 | 1 |
4.2%
|
|
| 2006 | 1 |
4.2%
|
|
| 2007 | 1 |
4.2%
|
|
| 2008 | 2 |
8.3%
|
|
| 2009 | 1 |
4.2%
|
|
| 2010 | 2 |
8.3%
|
|
| 2011 | 2 |
8.3%
|
|
| 2013 | 3 |
12.5%
|
|
| 2014 | 3 |
12.5%
|
|
| 2016 | 3 |
12.5%
|
|
| 2017 | 2 |
8.3%
|
|
| 2019 | 1 |
4.2%
|
|
| Sysmiss | 73 |