Value | Category | Cases | |
---|---|---|---|
-9 | Don't know (spontaneous) | 20 |
1%
|
1868 | 2 |
0.1%
|
|
1888 | 1 |
0.1%
|
|
1906 | 1 |
0.1%
|
|
1913 | 2 |
0.1%
|
|
1921 | 1 |
0.1%
|
|
1922 | 1 |
0.1%
|
|
1926 | 1 |
0.1%
|
|
1928 | 1 |
0.1%
|
|
1930 | 2 |
0.1%
|
|
1932 | 1 |
0.1%
|
|
1933 | 1 |
0.1%
|
|
1936 | 2 |
0.1%
|
|
1937 | 2 |
0.1%
|
|
1938 | 5 |
0.3%
|
|
1939 | 2 |
0.1%
|
|
1940 | 1 |
0.1%
|
|
1941 | 1 |
0.1%
|
|
1942 | 7 |
0.4%
|
|
1943 | 1 |
0.1%
|
|
1946 | 2 |
0.1%
|
|
1947 | 2 |
0.1%
|
|
1948 | 2 |
0.1%
|
|
1949 | 1 |
0.1%
|
|
1950 | 2 |
0.1%
|
|
1951 | 1 |
0.1%
|
|
1952 | 2 |
0.1%
|
|
1953 | 3 |
0.2%
|
|
1955 | 2 |
0.1%
|
|
1956 | 2 |
0.1%
|
|
1957 | 5 |
0.3%
|
|
1958 | 1 |
0.1%
|
|
1959 | 3 |
0.2%
|
|
1960 | 9 |
0.5%
|
|
1961 | 3 |
0.2%
|
|
1962 | 2 |
0.1%
|
|
1963 | 4 |
0.2%
|
|
1965 | 5 |
0.3%
|
|
1966 | 4 |
0.2%
|
|
1967 | 3 |
0.2%
|
|
1968 | 4 |
0.2%
|
|
1969 | 4 |
0.2%
|
|
1970 | 7 |
0.4%
|
|
1971 | 2 |
0.1%
|
|
1972 | 5 |
0.3%
|
|
1973 | 1 |
0.1%
|
|
1974 | 2 |
0.1%
|
|
1975 | 8 |
0.4%
|
|
1976 | 2 |
0.1%
|
|
1977 | 3 |
0.2%
|
|
1978 | 4 |
0.2%
|
|
1979 | 3 |
0.2%
|
|
1980 | 5 |
0.3%
|
|
1981 | 2 |
0.1%
|
|
1982 | 1 |
0.1%
|
|
1983 | 1 |
0.1%
|
|
1984 | 4 |
0.2%
|
|
1985 | 3 |
0.2%
|
|
1986 | 1 |
0.1%
|
|
1987 | 6 |
0.3%
|
|
1988 | 2 |
0.1%
|
|
1989 | 10 |
0.5%
|
|
1990 | 6 |
0.3%
|
|
1991 | 21 |
1.1%
|
|
1992 | 28 |
1.4%
|
|
1993 | 37 |
1.9%
|
|
1994 | 72 |
3.6%
|
|
1995 | 62 |
3.1%
|
|
1996 | 107 |
5.4%
|
|
1997 | 42 |
2.1%
|
|
1998 | 47 |
2.4%
|
|
1999 | 42 |
2.1%
|
|
2000 | 51 |
2.6%
|
|
2001 | 47 |
2.4%
|
|
2002 | 56 |
2.8%
|
|
2003 | 93 |
4.7%
|
|
2004 | 88 |
4.4%
|
|
2005 | 63 |
3.2%
|
|
2006 | 52 |
2.6%
|
|
2007 | 69 |
3.5%
|
|
2008 | 69 |
3.5%
|
|
2009 | 101 |
5.1%
|
|
2010 | 99 |
5%
|
|
2011 | 75 |
3.8%
|
|
2012 | 62 |
3.1%
|
|
2013 | 67 |
3.4%
|
|
2014 | 63 |
3.2%
|
|
2015 | 77 |
3.9%
|
|
2016 | 82 |
4.1%
|
|
2017 | 124 |
6.2%
|