| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 15 |
0.5%
|
| 1834 | 1 |
0%
|
|
| 1858 | 1 |
0%
|
|
| 1860 | 1 |
0%
|
|
| 1865 | 1 |
0%
|
|
| 1866 | 1 |
0%
|
|
| 1867 | 3 |
0.1%
|
|
| 1870 | 1 |
0%
|
|
| 1879 | 2 |
0.1%
|
|
| 1882 | 3 |
0.1%
|
|
| 1883 | 1 |
0%
|
|
| 1884 | 4 |
0.1%
|
|
| 1885 | 1 |
0%
|
|
| 1887 | 1 |
0%
|
|
| 1890 | 3 |
0.1%
|
|
| 1893 | 1 |
0%
|
|
| 1895 | 3 |
0.1%
|
|
| 1901 | 3 |
0.1%
|
|
| 1902 | 1 |
0%
|
|
| 1904 | 3 |
0.1%
|
|
| 1905 | 8 |
0.3%
|
|
| 1907 | 2 |
0.1%
|
|
| 1908 | 7 |
0.2%
|
|
| 1909 | 1 |
0%
|
|
| 1910 | 4 |
0.1%
|
|
| 1911 | 4 |
0.1%
|
|
| 1912 | 1 |
0%
|
|
| 1913 | 1 |
0%
|
|
| 1914 | 1 |
0%
|
|
| 1915 | 2 |
0.1%
|
|
| 1917 | 4 |
0.1%
|
|
| 1918 | 3 |
0.1%
|
|
| 1919 | 2 |
0.1%
|
|
| 1920 | 6 |
0.2%
|
|
| 1921 | 2 |
0.1%
|
|
| 1922 | 1 |
0%
|
|
| 1923 | 2 |
0.1%
|
|
| 1924 | 2 |
0.1%
|
|
| 1925 | 4 |
0.1%
|
|
| 1926 | 7 |
0.2%
|
|
| 1927 | 5 |
0.2%
|
|
| 1928 | 9 |
0.3%
|
|
| 1929 | 9 |
0.3%
|
|
| 1930 | 10 |
0.3%
|
|
| 1931 | 7 |
0.2%
|
|
| 1932 | 3 |
0.1%
|
|
| 1933 | 6 |
0.2%
|
|
| 1934 | 6 |
0.2%
|
|
| 1935 | 7 |
0.2%
|
|
| 1936 | 7 |
0.2%
|
|
| 1937 | 10 |
0.3%
|
|
| 1938 | 9 |
0.3%
|
|
| 1939 | 5 |
0.2%
|
|
| 1940 | 9 |
0.3%
|
|
| 1941 | 13 |
0.4%
|
|
| 1942 | 9 |
0.3%
|
|
| 1943 | 7 |
0.2%
|
|
| 1944 | 2 |
0.1%
|
|
| 1945 | 17 |
0.5%
|
|
| 1946 | 14 |
0.5%
|
|
| 1947 | 8 |
0.3%
|
|
| 1948 | 15 |
0.5%
|
|
| 1949 | 13 |
0.4%
|
|
| 1950 | 32 |
1%
|
|
| 1951 | 13 |
0.4%
|
|
| 1952 | 13 |
0.4%
|
|
| 1953 | 13 |
0.4%
|
|
| 1954 | 13 |
0.4%
|
|
| 1955 | 27 |
0.9%
|
|
| 1956 | 35 |
1.1%
|
|
| 1957 | 17 |
0.5%
|
|
| 1958 | 32 |
1%
|
|
| 1959 | 14 |
0.5%
|
|
| 1960 | 47 |
1.5%
|
|
| 1961 | 19 |
0.6%
|
|
| 1962 | 28 |
0.9%
|
|
| 1963 | 33 |
1.1%
|
|
| 1964 | 15 |
0.5%
|
|
| 1965 | 29 |
0.9%
|
|
| 1966 | 19 |
0.6%
|
|
| 1967 | 31 |
1%
|
|
| 1968 | 33 |
1.1%
|
|
| 1969 | 31 |
1%
|
|
| 1970 | 49 |
1.6%
|
|
| 1971 | 34 |
1.1%
|
|
| 1972 | 33 |
1.1%
|
|
| 1973 | 29 |
0.9%
|
|
| 1974 | 47 |
1.5%
|
|
| 1975 | 34 |
1.1%
|
|
| 1976 | 52 |
1.7%
|
|
| 1977 | 30 |
1%
|
|
| 1978 | 52 |
1.7%
|
|
| 1979 | 42 |
1.4%
|
|
| 1980 | 44 |
1.4%
|
|
| 1981 | 44 |
1.4%
|
|
| 1982 | 50 |
1.6%
|
|
| 1983 | 39 |
1.3%
|
|
| 1984 | 29 |
0.9%
|
|
| 1985 | 55 |
1.8%
|
|
| 1986 | 54 |
1.7%
|
|
| 1987 | 59 |
1.9%
|
|
| 1988 | 49 |
1.6%
|
|
| 1989 | 61 |
2%
|
|
| 1990 | 61 |
2%
|
|
| 1991 | 80 |
2.6%
|
|
| 1992 | 86 |
2.8%
|
|
| 1993 | 60 |
1.9%
|
|
| 1994 | 94 |
3%
|
|
| 1995 | 80 |
2.6%
|
|
| 1996 | 78 |
2.5%
|
|
| 1997 | 81 |
2.6%
|
|
| 1998 | 105 |
3.4%
|
|
| 1999 | 83 |
2.7%
|
|
| 2000 | 81 |
2.6%
|
|
| 2001 | 71 |
2.3%
|
|
| 2002 | 85 |
2.7%
|
|
| 2003 | 75 |
2.4%
|
|
| 2004 | 64 |
2.1%
|
|
| 2005 | 44 |
1.4%
|
|
| 2006 | 21 |
0.7%
|
|
| 2007 | 35 |
1.1%
|
|
| 2008 | 25 |
0.8%
|
|
| 2009 | 17 |
0.5%
|
|
| 2010 | 17 |
0.5%
|
|
| 2011 | 18 |
0.6%
|
|
| 2012 | 14 |
0.5%
|
|
| 2013 | 15 |
0.5%
|
|
| 2014 | 18 |
0.6%
|
|
| 2015 | 6 |
0.2%
|
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.