| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Never regiestered (spontaneous) | 0 |
0%
|
| 1926 | 2 |
0.6%
|
|
| 1929 | 1 |
0.3%
|
|
| 1932 | 1 |
0.3%
|
|
| 1936 | 2 |
0.6%
|
|
| 1938 | 1 |
0.3%
|
|
| 1940 | 1 |
0.3%
|
|
| 1941 | 1 |
0.3%
|
|
| 1943 | 1 |
0.3%
|
|
| 1947 | 1 |
0.3%
|
|
| 1950 | 1 |
0.3%
|
|
| 1953 | 1 |
0.3%
|
|
| 1955 | 1 |
0.3%
|
|
| 1956 | 2 |
0.6%
|
|
| 1957 | 1 |
0.3%
|
|
| 1959 | 1 |
0.3%
|
|
| 1960 | 1 |
0.3%
|
|
| 1961 | 1 |
0.3%
|
|
| 1963 | 1 |
0.3%
|
|
| 1964 | 1 |
0.3%
|
|
| 1966 | 1 |
0.3%
|
|
| 1968 | 2 |
0.6%
|
|
| 1970 | 2 |
0.6%
|
|
| 1972 | 1 |
0.3%
|
|
| 1973 | 2 |
0.6%
|
|
| 1976 | 1 |
0.3%
|
|
| 1977 | 3 |
0.8%
|
|
| 1978 | 1 |
0.3%
|
|
| 1979 | 1 |
0.3%
|
|
| 1983 | 1 |
0.3%
|
|
| 1987 | 1 |
0.3%
|
|
| 1988 | 1 |
0.3%
|
|
| 1989 | 1 |
0.3%
|
|
| 1990 | 2 |
0.6%
|
|
| 1991 | 9 |
2.5%
|
|
| 1992 | 8 |
2.2%
|
|
| 1993 | 15 |
4.2%
|
|
| 1994 | 10 |
2.8%
|
|
| 1995 | 18 |
5%
|
|
| 1996 | 10 |
2.8%
|
|
| 1997 | 14 |
3.9%
|
|
| 1998 | 16 |
4.4%
|
|
| 1999 | 10 |
2.8%
|
|
| 2000 | 2 |
0.6%
|
|
| 2001 | 11 |
3.1%
|
|
| 2002 | 16 |
4.4%
|
|
| 2003 | 19 |
5.3%
|
|
| 2004 | 21 |
5.8%
|
|
| 2005 | 11 |
3.1%
|
|
| 2006 | 18 |
5%
|
|
| 2007 | 14 |
3.9%
|
|
| 2008 | 15 |
4.2%
|
|
| 2009 | 12 |
3.3%
|
|
| 2010 | 10 |
2.8%
|
|
| 2011 | 14 |
3.9%
|
|
| 2012 | 10 |
2.8%
|
|
| 2013 | 9 |
2.5%
|
|
| 2014 | 12 |
3.3%
|
|
| 2015 | 4 |
1.1%
|
|
| 2016 | 7 |
1.9%
|
|
| 2017 | 3 |
0.8%
|