| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
0.5%
|
| 1865 | 1 |
0.1%
|
|
| 1867 | 1 |
0.1%
|
|
| 1882 | 1 |
0.1%
|
|
| 1884 | 1 |
0.1%
|
|
| 1901 | 1 |
0.1%
|
|
| 1905 | 1 |
0.1%
|
|
| 1908 | 1 |
0.1%
|
|
| 1910 | 1 |
0.1%
|
|
| 1911 | 1 |
0.1%
|
|
| 1913 | 1 |
0.1%
|
|
| 1914 | 1 |
0.1%
|
|
| 1915 | 1 |
0.1%
|
|
| 1918 | 1 |
0.1%
|
|
| 1922 | 1 |
0.1%
|
|
| 1925 | 4 |
0.4%
|
|
| 1927 | 1 |
0.1%
|
|
| 1928 | 1 |
0.1%
|
|
| 1929 | 3 |
0.3%
|
|
| 1930 | 1 |
0.1%
|
|
| 1933 | 1 |
0.1%
|
|
| 1934 | 1 |
0.1%
|
|
| 1935 | 2 |
0.2%
|
|
| 1936 | 3 |
0.3%
|
|
| 1937 | 3 |
0.3%
|
|
| 1938 | 1 |
0.1%
|
|
| 1939 | 1 |
0.1%
|
|
| 1941 | 2 |
0.2%
|
|
| 1945 | 5 |
0.5%
|
|
| 1946 | 3 |
0.3%
|
|
| 1947 | 6 |
0.6%
|
|
| 1948 | 3 |
0.3%
|
|
| 1949 | 2 |
0.2%
|
|
| 1950 | 6 |
0.6%
|
|
| 1951 | 1 |
0.1%
|
|
| 1952 | 3 |
0.3%
|
|
| 1953 | 1 |
0.1%
|
|
| 1954 | 5 |
0.5%
|
|
| 1955 | 6 |
0.6%
|
|
| 1956 | 5 |
0.5%
|
|
| 1957 | 4 |
0.4%
|
|
| 1958 | 7 |
0.7%
|
|
| 1959 | 6 |
0.6%
|
|
| 1960 | 12 |
1.2%
|
|
| 1961 | 3 |
0.3%
|
|
| 1962 | 8 |
0.8%
|
|
| 1963 | 14 |
1.4%
|
|
| 1964 | 5 |
0.5%
|
|
| 1965 | 10 |
1%
|
|
| 1966 | 5 |
0.5%
|
|
| 1967 | 7 |
0.7%
|
|
| 1968 | 7 |
0.7%
|
|
| 1969 | 12 |
1.2%
|
|
| 1970 | 8 |
0.8%
|
|
| 1971 | 12 |
1.2%
|
|
| 1972 | 10 |
1%
|
|
| 1973 | 6 |
0.6%
|
|
| 1974 | 15 |
1.5%
|
|
| 1975 | 4 |
0.4%
|
|
| 1976 | 6 |
0.6%
|
|
| 1977 | 7 |
0.7%
|
|
| 1978 | 13 |
1.3%
|
|
| 1979 | 8 |
0.8%
|
|
| 1980 | 12 |
1.2%
|
|
| 1981 | 8 |
0.8%
|
|
| 1982 | 12 |
1.2%
|
|
| 1983 | 14 |
1.4%
|
|
| 1984 | 8 |
0.8%
|
|
| 1985 | 12 |
1.2%
|
|
| 1986 | 18 |
1.8%
|
|
| 1987 | 18 |
1.8%
|
|
| 1988 | 17 |
1.7%
|
|
| 1989 | 18 |
1.8%
|
|
| 1990 | 19 |
1.9%
|
|
| 1991 | 22 |
2.2%
|
|
| 1992 | 26 |
2.6%
|
|
| 1993 | 13 |
1.3%
|
|
| 1994 | 26 |
2.6%
|
|
| 1995 | 23 |
2.3%
|
|
| 1996 | 25 |
2.5%
|
|
| 1997 | 32 |
3.2%
|
|
| 1998 | 25 |
2.5%
|
|
| 1999 | 32 |
3.2%
|
|
| 2000 | 23 |
2.3%
|
|
| 2001 | 27 |
2.7%
|
|
| 2002 | 35 |
3.5%
|
|
| 2003 | 34 |
3.4%
|
|
| 2004 | 24 |
2.4%
|
|
| 2005 | 28 |
2.8%
|
|
| 2006 | 17 |
1.7%
|
|
| 2007 | 23 |
2.3%
|
|
| 2008 | 20 |
2%
|
|
| 2009 | 14 |
1.4%
|
|
| 2010 | 17 |
1.7%
|
|
| 2011 | 18 |
1.8%
|
|
| 2012 | 14 |
1.4%
|
|
| 2013 | 15 |
1.5%
|
|
| 2014 | 18 |
1.8%
|
|
| 2015 | 6 |
0.6%
|
This site uses cookies to optimize functionality and give you the best possible experience. If you continue to navigate this website beyond this page, cookies will be placed on your browser. To learn more about cookies, click here.