| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 50 |
2.5%
|
| 1984 | 1 |
0%
|
|
| 1987 | 2 |
0.1%
|
|
| 1990 | 2 |
0.1%
|
|
| 1993 | 2 |
0.1%
|
|
| 1994 | 1 |
0%
|
|
| 1995 | 6 |
0.3%
|
|
| 1997 | 3 |
0.1%
|
|
| 1998 | 6 |
0.3%
|
|
| 1999 | 1 |
0%
|
|
| 2000 | 29 |
1.4%
|
|
| 2001 | 11 |
0.5%
|
|
| 2002 | 16 |
0.8%
|
|
| 2003 | 18 |
0.9%
|
|
| 2004 | 50 |
2.5%
|
|
| 2005 | 205 |
10.2%
|
|
| 2006 | 192 |
9.5%
|
|
| 2007 | 32 |
1.6%
|
|
| 2008 | 80 |
4%
|
|
| 2009 | 258 |
12.8%
|
|
| 2010 | 351 |
17.4%
|
|
| 2011 | 12 |
0.6%
|
|
| 2012 | 15 |
0.7%
|
|
| 2013 | 16 |
0.8%
|
|
| 2014 | 49 |
2.4%
|
|
| 2015 | 85 |
4.2%
|
|
| 2016 | 274 |
13.6%
|
|
| 2017 | 244 |
12.1%
|
|
| 2018 | 7 |
0.3%
|
|
| Sysmiss | 617 |