Value | Category | Cases | |
---|---|---|---|
-9 | Don't know (spontaneous) | 3 |
0.7%
|
1825 | 1 |
0.2%
|
|
1860 | 1 |
0.2%
|
|
1873 | 1 |
0.2%
|
|
1881 | 1 |
0.2%
|
|
1921 | 1 |
0.2%
|
|
1929 | 1 |
0.2%
|
|
1946 | 2 |
0.5%
|
|
1947 | 2 |
0.5%
|
|
1948 | 3 |
0.7%
|
|
1950 | 2 |
0.5%
|
|
1952 | 2 |
0.5%
|
|
1954 | 4 |
1%
|
|
1955 | 2 |
0.5%
|
|
1956 | 2 |
0.5%
|
|
1957 | 1 |
0.2%
|
|
1958 | 2 |
0.5%
|
|
1960 | 3 |
0.7%
|
|
1961 | 1 |
0.2%
|
|
1963 | 1 |
0.2%
|
|
1965 | 1 |
0.2%
|
|
1967 | 1 |
0.2%
|
|
1969 | 2 |
0.5%
|
|
1971 | 3 |
0.7%
|
|
1974 | 3 |
0.7%
|
|
1975 | 3 |
0.7%
|
|
1976 | 1 |
0.2%
|
|
1977 | 2 |
0.5%
|
|
1978 | 2 |
0.5%
|
|
1979 | 2 |
0.5%
|
|
1980 | 1 |
0.2%
|
|
1981 | 1 |
0.2%
|
|
1982 | 1 |
0.2%
|
|
1983 | 2 |
0.5%
|
|
1985 | 4 |
1%
|
|
1986 | 3 |
0.7%
|
|
1987 | 1 |
0.2%
|
|
1988 | 3 |
0.7%
|
|
1989 | 21 |
5.1%
|
|
1990 | 31 |
7.6%
|
|
1991 | 31 |
7.6%
|
|
1992 | 24 |
5.9%
|
|
1993 | 24 |
5.9%
|
|
1994 | 11 |
2.7%
|
|
1995 | 9 |
2.2%
|
|
1996 | 11 |
2.7%
|
|
1997 | 13 |
3.2%
|
|
1998 | 8 |
2%
|
|
1999 | 4 |
1%
|
|
2000 | 11 |
2.7%
|
|
2001 | 9 |
2.2%
|
|
2002 | 6 |
1.5%
|
|
2003 | 15 |
3.7%
|
|
2004 | 9 |
2.2%
|
|
2005 | 8 |
2%
|
|
2006 | 6 |
1.5%
|
|
2007 | 12 |
2.9%
|
|
2008 | 7 |
1.7%
|
|
2009 | 8 |
2%
|
|
2010 | 12 |
2.9%
|
|
2011 | 9 |
2.2%
|
|
2012 | 10 |
2.4%
|
|
2013 | 6 |
1.5%
|
|
2014 | 12 |
2.9%
|
|
2015 | 2 |
0.5%
|
|
2016 | 6 |
1.5%
|
|
2017 | 2 |
0.5%
|