| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 103 |
12.4%
|
| 1976 | 1 |
0.1%
|
|
| 1984 | 1 |
0.1%
|
|
| 1988 | 1 |
0.1%
|
|
| 1989 | 2 |
0.2%
|
|
| 1990 | 4 |
0.5%
|
|
| 1991 | 2 |
0.2%
|
|
| 1992 | 1 |
0.1%
|
|
| 1994 | 2 |
0.2%
|
|
| 1995 | 3 |
0.4%
|
|
| 1996 | 1 |
0.1%
|
|
| 1997 | 5 |
0.6%
|
|
| 1998 | 9 |
1.1%
|
|
| 1999 | 16 |
1.9%
|
|
| 2000 | 23 |
2.8%
|
|
| 2001 | 1 |
0.1%
|
|
| 2002 | 6 |
0.7%
|
|
| 2003 | 4 |
0.5%
|
|
| 2004 | 12 |
1.4%
|
|
| 2005 | 25 |
3%
|
|
| 2006 | 9 |
1.1%
|
|
| 2007 | 24 |
2.9%
|
|
| 2008 | 57 |
6.9%
|
|
| 2009 | 42 |
5.1%
|
|
| 2010 | 77 |
9.3%
|
|
| 2011 | 30 |
3.6%
|
|
| 2012 | 40 |
4.8%
|
|
| 2013 | 27 |
3.3%
|
|
| 2014 | 59 |
7.1%
|
|
| 2015 | 69 |
8.3%
|
|
| 2016 | 48 |
5.8%
|
|
| 2017 | 48 |
5.8%
|
|
| 2018 | 37 |
4.5%
|
|
| 2019 | 24 |
2.9%
|
|
| 2020 | 12 |
1.4%
|
|
| 2021 | 3 |
0.4%
|
|
| Sysmiss | 9844 |