| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
9.2%
|
| 1983 | 2 |
1.5%
|
|
| 1985 | 1 |
0.8%
|
|
| 1986 | 1 |
0.8%
|
|
| 1988 | 1 |
0.8%
|
|
| 1990 | 1 |
0.8%
|
|
| 1991 | 3 |
2.3%
|
|
| 1992 | 2 |
1.5%
|
|
| 1993 | 1 |
0.8%
|
|
| 1994 | 1 |
0.8%
|
|
| 1996 | 1 |
0.8%
|
|
| 1997 | 4 |
3.1%
|
|
| 2000 | 5 |
3.8%
|
|
| 2001 | 2 |
1.5%
|
|
| 2002 | 3 |
2.3%
|
|
| 2003 | 8 |
6.1%
|
|
| 2004 | 3 |
2.3%
|
|
| 2005 | 3 |
2.3%
|
|
| 2006 | 8 |
6.1%
|
|
| 2007 | 7 |
5.3%
|
|
| 2008 | 4 |
3.1%
|
|
| 2009 | 7 |
5.3%
|
|
| 2010 | 3 |
2.3%
|
|
| 2011 | 5 |
3.8%
|
|
| 2012 | 6 |
4.6%
|
|
| 2013 | 3 |
2.3%
|
|
| 2014 | 3 |
2.3%
|
|
| 2015 | 3 |
2.3%
|
|
| 2016 | 12 |
9.2%
|
|
| 2017 | 8 |
6.1%
|
|
| 2018 | 6 |
4.6%
|
|
| 2020 | 1 |
0.8%
|
|
| 2022 | 1 |
0.8%
|
|
| Sysmiss | 867 |