| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
21.4%
|
| 1994 | 1 |
3.6%
|
|
| 1997 | 1 |
3.6%
|
|
| 1998 | 1 |
3.6%
|
|
| 2002 | 1 |
3.6%
|
|
| 2005 | 1 |
3.6%
|
|
| 2007 | 1 |
3.6%
|
|
| 2008 | 1 |
3.6%
|
|
| 2011 | 1 |
3.6%
|
|
| 2012 | 1 |
3.6%
|
|
| 2014 | 2 |
7.1%
|
|
| 2015 | 3 |
10.7%
|
|
| 2016 | 2 |
7.1%
|
|
| 2018 | 3 |
10.7%
|
|
| 2021 | 2 |
7.1%
|
|
| 2022 | 1 |
3.6%
|
|
| Sysmiss | 134 |