Value | Category | Cases | |
---|---|---|---|
-9 | Don't know (spontaneous) | 8 |
0.7%
|
1882 | 1 |
0.1%
|
|
1923 | 1 |
0.1%
|
|
1936 | 1 |
0.1%
|
|
1945 | 3 |
0.3%
|
|
1946 | 5 |
0.5%
|
|
1947 | 9 |
0.8%
|
|
1948 | 4 |
0.4%
|
|
1950 | 2 |
0.2%
|
|
1952 | 5 |
0.5%
|
|
1953 | 1 |
0.1%
|
|
1954 | 2 |
0.2%
|
|
1955 | 1 |
0.1%
|
|
1956 | 3 |
0.3%
|
|
1957 | 6 |
0.6%
|
|
1958 | 4 |
0.4%
|
|
1959 | 1 |
0.1%
|
|
1960 | 1 |
0.1%
|
|
1963 | 2 |
0.2%
|
|
1964 | 3 |
0.3%
|
|
1966 | 2 |
0.2%
|
|
1967 | 2 |
0.2%
|
|
1968 | 5 |
0.5%
|
|
1969 | 1 |
0.1%
|
|
1972 | 3 |
0.3%
|
|
1973 | 3 |
0.3%
|
|
1974 | 4 |
0.4%
|
|
1975 | 3 |
0.3%
|
|
1976 | 1 |
0.1%
|
|
1977 | 2 |
0.2%
|
|
1978 | 3 |
0.3%
|
|
1979 | 1 |
0.1%
|
|
1980 | 1 |
0.1%
|
|
1981 | 1 |
0.1%
|
|
1982 | 3 |
0.3%
|
|
1983 | 3 |
0.3%
|
|
1984 | 5 |
0.5%
|
|
1986 | 1 |
0.1%
|
|
1987 | 6 |
0.6%
|
|
1988 | 4 |
0.4%
|
|
1989 | 24 |
2.2%
|
|
1990 | 48 |
4.4%
|
|
1991 | 52 |
4.8%
|
|
1992 | 79 |
7.3%
|
|
1993 | 70 |
6.4%
|
|
1994 | 62 |
5.7%
|
|
1995 | 50 |
4.6%
|
|
1996 | 45 |
4.1%
|
|
1997 | 30 |
2.8%
|
|
1998 | 43 |
4%
|
|
1999 | 33 |
3%
|
|
2000 | 43 |
4%
|
|
2001 | 48 |
4.4%
|
|
2002 | 32 |
2.9%
|
|
2003 | 43 |
4%
|
|
2004 | 31 |
2.9%
|
|
2005 | 50 |
4.6%
|
|
2006 | 42 |
3.9%
|
|
2007 | 36 |
3.3%
|
|
2008 | 23 |
2.1%
|
|
2009 | 26 |
2.4%
|
|
2010 | 16 |
1.5%
|
|
2011 | 7 |
0.6%
|
|
2012 | 9 |
0.8%
|
|
2013 | 8 |
0.7%
|
|
2014 | 3 |
0.3%
|
|
2015 | 5 |
0.5%
|
|
2016 | 6 |
0.6%
|
|
2017 | 5 |
0.5%
|