| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 11 |
16.4%
|
| 1952 | 1 |
1.5%
|
|
| 1973 | 1 |
1.5%
|
|
| 1974 | 1 |
1.5%
|
|
| 1979 | 1 |
1.5%
|
|
| 1982 | 1 |
1.5%
|
|
| 1993 | 2 |
3%
|
|
| 1994 | 1 |
1.5%
|
|
| 1998 | 1 |
1.5%
|
|
| 1999 | 2 |
3%
|
|
| 2000 | 1 |
1.5%
|
|
| 2003 | 1 |
1.5%
|
|
| 2005 | 2 |
3%
|
|
| 2006 | 1 |
1.5%
|
|
| 2007 | 1 |
1.5%
|
|
| 2008 | 1 |
1.5%
|
|
| 2009 | 1 |
1.5%
|
|
| 2010 | 7 |
10.4%
|
|
| 2011 | 1 |
1.5%
|
|
| 2012 | 3 |
4.5%
|
|
| 2013 | 3 |
4.5%
|
|
| 2014 | 4 |
6%
|
|
| 2015 | 3 |
4.5%
|
|
| 2017 | 2 |
3%
|
|
| 2018 | 4 |
6%
|
|
| 2019 | 4 |
6%
|
|
| 2020 | 2 |
3%
|
|
| 2021 | 1 |
1.5%
|
|
| 2022 | 3 |
4.5%
|
|
| Sysmiss | 298 |