| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 20 |
7.2%
|
| 1930 | 1 |
0.4%
|
|
| 1965 | 1 |
0.4%
|
|
| 1970 | 1 |
0.4%
|
|
| 1972 | 1 |
0.4%
|
|
| 1978 | 2 |
0.7%
|
|
| 1980 | 2 |
0.7%
|
|
| 1983 | 2 |
0.7%
|
|
| 1985 | 2 |
0.7%
|
|
| 1988 | 2 |
0.7%
|
|
| 1989 | 1 |
0.4%
|
|
| 1990 | 7 |
2.5%
|
|
| 1991 | 1 |
0.4%
|
|
| 1992 | 3 |
1.1%
|
|
| 1993 | 2 |
0.7%
|
|
| 1994 | 2 |
0.7%
|
|
| 1995 | 5 |
1.8%
|
|
| 1996 | 4 |
1.4%
|
|
| 1997 | 6 |
2.2%
|
|
| 1998 | 2 |
0.7%
|
|
| 1999 | 2 |
0.7%
|
|
| 2000 | 9 |
3.2%
|
|
| 2001 | 4 |
1.4%
|
|
| 2002 | 9 |
3.2%
|
|
| 2003 | 2 |
0.7%
|
|
| 2004 | 4 |
1.4%
|
|
| 2005 | 9 |
3.2%
|
|
| 2006 | 10 |
3.6%
|
|
| 2007 | 5 |
1.8%
|
|
| 2008 | 11 |
4%
|
|
| 2009 | 10 |
3.6%
|
|
| 2010 | 11 |
4%
|
|
| 2011 | 5 |
1.8%
|
|
| 2012 | 18 |
6.5%
|
|
| 2013 | 8 |
2.9%
|
|
| 2014 | 13 |
4.7%
|
|
| 2015 | 12 |
4.3%
|
|
| 2016 | 13 |
4.7%
|
|
| 2017 | 10 |
3.6%
|
|
| 2018 | 16 |
5.8%
|
|
| 2019 | 14 |
5%
|
|
| 2020 | 5 |
1.8%
|
|
| 2021 | 5 |
1.8%
|
|
| 2022 | 6 |
2.2%
|
|
| Sysmiss | 709 |