| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 16 |
7.4%
|
| 1905 | 1 |
0.5%
|
|
| 1944 | 1 |
0.5%
|
|
| 1950 | 1 |
0.5%
|
|
| 1957 | 1 |
0.5%
|
|
| 1960 | 2 |
0.9%
|
|
| 1967 | 1 |
0.5%
|
|
| 1974 | 1 |
0.5%
|
|
| 1980 | 3 |
1.4%
|
|
| 1989 | 1 |
0.5%
|
|
| 1990 | 2 |
0.9%
|
|
| 1991 | 3 |
1.4%
|
|
| 1992 | 7 |
3.3%
|
|
| 1993 | 8 |
3.7%
|
|
| 1994 | 8 |
3.7%
|
|
| 1995 | 11 |
5.1%
|
|
| 1996 | 5 |
2.3%
|
|
| 1997 | 7 |
3.3%
|
|
| 1998 | 8 |
3.7%
|
|
| 1999 | 5 |
2.3%
|
|
| 2000 | 11 |
5.1%
|
|
| 2001 | 2 |
0.9%
|
|
| 2002 | 6 |
2.8%
|
|
| 2003 | 4 |
1.9%
|
|
| 2004 | 5 |
2.3%
|
|
| 2005 | 9 |
4.2%
|
|
| 2006 | 5 |
2.3%
|
|
| 2007 | 10 |
4.7%
|
|
| 2008 | 1 |
0.5%
|
|
| 2009 | 3 |
1.4%
|
|
| 2010 | 8 |
3.7%
|
|
| 2011 | 3 |
1.4%
|
|
| 2012 | 12 |
5.6%
|
|
| 2013 | 5 |
2.3%
|
|
| 2014 | 7 |
3.3%
|
|
| 2015 | 4 |
1.9%
|
|
| 2016 | 5 |
2.3%
|
|
| 2017 | 3 |
1.4%
|
|
| 2018 | 8 |
3.7%
|
|
| 2019 | 2 |
0.9%
|
|
| 2020 | 6 |
2.8%
|
|
| 2021 | 4 |
1.9%
|
|
| Sysmiss | 259 |