| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 30 |
0.1%
|
| 1838 | 1 |
0%
|
|
| 1863 | 1 |
0%
|
|
| 1872 | 1 |
0%
|
|
| 1873 | 1 |
0%
|
|
| 1878 | 3 |
0%
|
|
| 1882 | 1 |
0%
|
|
| 1887 | 2 |
0%
|
|
| 1889 | 1 |
0%
|
|
| 1896 | 1 |
0%
|
|
| 1897 | 1 |
0%
|
|
| 1900 | 1 |
0%
|
|
| 1901 | 1 |
0%
|
|
| 1902 | 3 |
0%
|
|
| 1903 | 1 |
0%
|
|
| 1909 | 1 |
0%
|
|
| 1910 | 1 |
0%
|
|
| 1912 | 2 |
0%
|
|
| 1913 | 2 |
0%
|
|
| 1914 | 2 |
0%
|
|
| 1915 | 3 |
0%
|
|
| 1916 | 1 |
0%
|
|
| 1917 | 5 |
0%
|
|
| 1918 | 4 |
0%
|
|
| 1919 | 2 |
0%
|
|
| 1920 | 7 |
0%
|
|
| 1921 | 4 |
0%
|
|
| 1922 | 3 |
0%
|
|
| 1925 | 2 |
0%
|
|
| 1926 | 2 |
0%
|
|
| 1927 | 7 |
0%
|
|
| 1928 | 1 |
0%
|
|
| 1929 | 3 |
0%
|
|
| 1930 | 29 |
0.1%
|
|
| 1931 | 8 |
0%
|
|
| 1932 | 5 |
0%
|
|
| 1933 | 7 |
0%
|
|
| 1934 | 8 |
0%
|
|
| 1935 | 13 |
0%
|
|
| 1936 | 10 |
0%
|
|
| 1937 | 5 |
0%
|
|
| 1938 | 6 |
0%
|
|
| 1939 | 5 |
0%
|
|
| 1940 | 11 |
0%
|
|
| 1941 | 6 |
0%
|
|
| 1942 | 4 |
0%
|
|
| 1943 | 13 |
0%
|
|
| 1944 | 6 |
0%
|
|
| 1945 | 13 |
0%
|
|
| 1946 | 13 |
0%
|
|
| 1947 | 26 |
0.1%
|
|
| 1948 | 17 |
0.1%
|
|
| 1949 | 16 |
0.1%
|
|
| 1950 | 29 |
0.1%
|
|
| 1951 | 16 |
0.1%
|
|
| 1952 | 35 |
0.1%
|
|
| 1953 | 8 |
0%
|
|
| 1954 | 21 |
0.1%
|
|
| 1955 | 30 |
0.1%
|
|
| 1956 | 33 |
0.1%
|
|
| 1957 | 24 |
0.1%
|
|
| 1958 | 36 |
0.1%
|
|
| 1959 | 32 |
0.1%
|
|
| 1960 | 96 |
0.3%
|
|
| 1961 | 45 |
0.2%
|
|
| 1962 | 67 |
0.2%
|
|
| 1963 | 48 |
0.2%
|
|
| 1964 | 63 |
0.2%
|
|
| 1965 | 94 |
0.3%
|
|
| 1966 | 45 |
0.2%
|
|
| 1967 | 78 |
0.3%
|
|
| 1968 | 65 |
0.2%
|
|
| 1969 | 74 |
0.3%
|
|
| 1970 | 160 |
0.5%
|
|
| 1971 | 86 |
0.3%
|
|
| 1972 | 139 |
0.5%
|
|
| 1973 | 106 |
0.4%
|
|
| 1974 | 134 |
0.5%
|
|
| 1975 | 156 |
0.5%
|
|
| 1976 | 138 |
0.5%
|
|
| 1977 | 95 |
0.3%
|
|
| 1978 | 161 |
0.6%
|
|
| 1979 | 151 |
0.5%
|
|
| 1980 | 434 |
1.5%
|
|
| 1981 | 174 |
0.6%
|
|
| 1982 | 271 |
0.9%
|
|
| 1983 | 218 |
0.7%
|
|
| 1984 | 286 |
1%
|
|
| 1985 | 458 |
1.6%
|
|
| 1986 | 293 |
1%
|
|
| 1987 | 274 |
0.9%
|
|
| 1988 | 287 |
1%
|
|
| 1989 | 348 |
1.2%
|
|
| 1990 | 701 |
2.4%
|
|
| 1991 | 348 |
1.2%
|
|
| 1992 | 481 |
1.7%
|
|
| 1993 | 373 |
1.3%
|
|
| 1994 | 459 |
1.6%
|
|
| 1995 | 876 |
3%
|
|
| 1996 | 556 |
1.9%
|
|
| 1997 | 515 |
1.8%
|
|
| 1998 | 881 |
3%
|
|
| 1999 | 580 |
2%
|
|
| 2000 | 1114 |
3.8%
|
|
| 2001 | 853 |
2.9%
|
|
| 2002 | 957 |
3.3%
|
|
| 2003 | 861 |
3%
|
|
| 2004 | 990 |
3.4%
|
|
| 2005 | 1285 |
4.4%
|
|
| 2006 | 976 |
3.3%
|
|
| 2007 | 959 |
3.3%
|
|
| 2008 | 960 |
3.3%
|
|
| 2009 | 802 |
2.8%
|
|
| 2010 | 1186 |
4.1%
|
|
| 2011 | 770 |
2.6%
|
|
| 2012 | 793 |
2.7%
|
|
| 2013 | 472 |
1.6%
|
|
| 2014 | 564 |
1.9%
|
|
| 2015 | 739 |
2.5%
|
|
| 2016 | 547 |
1.9%
|
|
| 2017 | 688 |
2.4%
|
|
| 2018 | 862 |
3%
|
|
| 2019 | 393 |
1.3%
|
|
| 2020 | 301 |
1%
|
|
| 2021 | 329 |
1.1%
|
|
| 2022 | 253 |
0.9%
|
|
| 2023 | 68 |
0.2%
|
|
| 2024 | 12 |
0%
|
|
| 2025 | 2 |
0%
|