| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 27 |
1.9%
|
| 1964 | 1 |
0.1%
|
|
| 1970 | 1 |
0.1%
|
|
| 1972 | 1 |
0.1%
|
|
| 1978 | 1 |
0.1%
|
|
| 1979 | 1 |
0.1%
|
|
| 1981 | 4 |
0.3%
|
|
| 1982 | 2 |
0.1%
|
|
| 1983 | 2 |
0.1%
|
|
| 1986 | 2 |
0.1%
|
|
| 1987 | 1 |
0.1%
|
|
| 1988 | 3 |
0.2%
|
|
| 1989 | 2 |
0.1%
|
|
| 1990 | 10 |
0.7%
|
|
| 1991 | 2 |
0.1%
|
|
| 1993 | 2 |
0.1%
|
|
| 1995 | 2 |
0.1%
|
|
| 1996 | 3 |
0.2%
|
|
| 1997 | 5 |
0.4%
|
|
| 1998 | 6 |
0.4%
|
|
| 1999 | 7 |
0.5%
|
|
| 2000 | 41 |
2.9%
|
|
| 2001 | 9 |
0.6%
|
|
| 2002 | 11 |
0.8%
|
|
| 2003 | 11 |
0.8%
|
|
| 2004 | 11 |
0.8%
|
|
| 2005 | 21 |
1.5%
|
|
| 2006 | 14 |
1%
|
|
| 2007 | 18 |
1.3%
|
|
| 2008 | 16 |
1.1%
|
|
| 2009 | 18 |
1.3%
|
|
| 2010 | 40 |
2.8%
|
|
| 2011 | 18 |
1.3%
|
|
| 2012 | 43 |
3%
|
|
| 2013 | 24 |
1.7%
|
|
| 2014 | 39 |
2.8%
|
|
| 2015 | 93 |
6.6%
|
|
| 2016 | 50 |
3.5%
|
|
| 2017 | 84 |
6%
|
|
| 2018 | 166 |
11.8%
|
|
| 2019 | 197 |
14%
|
|
| 2020 | 143 |
10.1%
|
|
| 2021 | 148 |
10.5%
|
|
| 2022 | 110 |
7.8%
|