Value | Category | Cases | |
---|---|---|---|
-9 | Don't know (spontaneous) | 0 |
0%
|
1892 | 1 |
0.2%
|
|
1894 | 1 |
0.2%
|
|
1906 | 1 |
0.2%
|
|
1911 | 1 |
0.2%
|
|
1920 | 1 |
0.2%
|
|
1921 | 1 |
0.2%
|
|
1927 | 1 |
0.2%
|
|
1930 | 1 |
0.2%
|
|
1943 | 1 |
0.2%
|
|
1945 | 1 |
0.2%
|
|
1947 | 2 |
0.5%
|
|
1948 | 1 |
0.2%
|
|
1949 | 1 |
0.2%
|
|
1951 | 1 |
0.2%
|
|
1953 | 3 |
0.7%
|
|
1954 | 2 |
0.5%
|
|
1955 | 3 |
0.7%
|
|
1957 | 1 |
0.2%
|
|
1958 | 1 |
0.2%
|
|
1960 | 2 |
0.5%
|
|
1965 | 2 |
0.5%
|
|
1968 | 2 |
0.5%
|
|
1970 | 2 |
0.5%
|
|
1971 | 1 |
0.2%
|
|
1972 | 1 |
0.2%
|
|
1974 | 1 |
0.2%
|
|
1976 | 2 |
0.5%
|
|
1977 | 1 |
0.2%
|
|
1978 | 1 |
0.2%
|
|
1980 | 1 |
0.2%
|
|
1982 | 1 |
0.2%
|
|
1984 | 1 |
0.2%
|
|
1988 | 4 |
1%
|
|
1989 | 2 |
0.5%
|
|
1990 | 36 |
8.9%
|
|
1991 | 27 |
6.7%
|
|
1992 | 28 |
6.9%
|
|
1993 | 21 |
5.2%
|
|
1994 | 35 |
8.7%
|
|
1995 | 16 |
4%
|
|
1996 | 22 |
5.4%
|
|
1997 | 16 |
4%
|
|
1998 | 13 |
3.2%
|
|
1999 | 10 |
2.5%
|
|
2000 | 11 |
2.7%
|
|
2001 | 8 |
2%
|
|
2002 | 10 |
2.5%
|
|
2003 | 7 |
1.7%
|
|
2004 | 3 |
0.7%
|
|
2005 | 3 |
0.7%
|
|
2006 | 5 |
1.2%
|
|
2007 | 8 |
2%
|
|
2008 | 4 |
1%
|
|
2009 | 9 |
2.2%
|
|
2010 | 12 |
3%
|
|
2011 | 14 |
3.5%
|
|
2012 | 10 |
2.5%
|
|
2013 | 13 |
3.2%
|
|
2014 | 9 |
2.2%
|
|
2015 | 4 |
1%
|
|
2016 | 1 |
0.2%
|