| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Never regiestered (spontaneous) | 0 |
0%
|
| 1936 | 1 |
0.3%
|
|
| 1947 | 1 |
0.3%
|
|
| 1957 | 1 |
0.3%
|
|
| 1958 | 1 |
0.3%
|
|
| 1963 | 1 |
0.3%
|
|
| 1964 | 3 |
0.8%
|
|
| 1966 | 1 |
0.3%
|
|
| 1969 | 1 |
0.3%
|
|
| 1975 | 1 |
0.3%
|
|
| 1984 | 1 |
0.3%
|
|
| 1987 | 2 |
0.6%
|
|
| 1990 | 1 |
0.3%
|
|
| 1991 | 9 |
2.5%
|
|
| 1992 | 5 |
1.4%
|
|
| 1993 | 11 |
3.1%
|
|
| 1994 | 7 |
2%
|
|
| 1995 | 12 |
3.4%
|
|
| 1996 | 16 |
4.5%
|
|
| 1997 | 9 |
2.5%
|
|
| 1998 | 16 |
4.5%
|
|
| 1999 | 10 |
2.8%
|
|
| 2000 | 12 |
3.4%
|
|
| 2001 | 6 |
1.7%
|
|
| 2002 | 9 |
2.5%
|
|
| 2003 | 16 |
4.5%
|
|
| 2004 | 13 |
3.7%
|
|
| 2005 | 10 |
2.8%
|
|
| 2006 | 14 |
4%
|
|
| 2007 | 21 |
5.9%
|
|
| 2008 | 14 |
4%
|
|
| 2009 | 13 |
3.7%
|
|
| 2010 | 9 |
2.5%
|
|
| 2011 | 9 |
2.5%
|
|
| 2012 | 8 |
2.3%
|
|
| 2013 | 14 |
4%
|
|
| 2014 | 14 |
4%
|
|
| 2015 | 11 |
3.1%
|
|
| 2016 | 8 |
2.3%
|
|
| 2017 | 12 |
3.4%
|
|
| 2018 | 8 |
2.3%
|
|
| 2019 | 12 |
3.4%
|
|
| 2020 | 4 |
1.1%
|
|
| 2021 | 3 |
0.8%
|
|
| 2022 | 4 |
1.1%
|