Value | Category | Cases | |
---|---|---|---|
-9 | Don't know (spontaneous) | 20 |
1.5%
|
1880 | 1 |
0.1%
|
|
1896 | 1 |
0.1%
|
|
1911 | 2 |
0.1%
|
|
1912 | 1 |
0.1%
|
|
1927 | 1 |
0.1%
|
|
1928 | 3 |
0.2%
|
|
1929 | 1 |
0.1%
|
|
1930 | 2 |
0.1%
|
|
1932 | 1 |
0.1%
|
|
1933 | 1 |
0.1%
|
|
1934 | 3 |
0.2%
|
|
1935 | 3 |
0.2%
|
|
1936 | 5 |
0.4%
|
|
1937 | 1 |
0.1%
|
|
1940 | 1 |
0.1%
|
|
1943 | 2 |
0.1%
|
|
1944 | 1 |
0.1%
|
|
1945 | 3 |
0.2%
|
|
1946 | 7 |
0.5%
|
|
1947 | 3 |
0.2%
|
|
1949 | 1 |
0.1%
|
|
1951 | 1 |
0.1%
|
|
1952 | 3 |
0.2%
|
|
1954 | 2 |
0.1%
|
|
1955 | 3 |
0.2%
|
|
1956 | 6 |
0.4%
|
|
1957 | 2 |
0.1%
|
|
1958 | 4 |
0.3%
|
|
1959 | 1 |
0.1%
|
|
1960 | 1 |
0.1%
|
|
1961 | 2 |
0.1%
|
|
1962 | 2 |
0.1%
|
|
1963 | 2 |
0.1%
|
|
1964 | 5 |
0.4%
|
|
1965 | 3 |
0.2%
|
|
1966 | 3 |
0.2%
|
|
1967 | 2 |
0.1%
|
|
1968 | 1 |
0.1%
|
|
1969 | 1 |
0.1%
|
|
1970 | 1 |
0.1%
|
|
1971 | 2 |
0.1%
|
|
1972 | 5 |
0.4%
|
|
1973 | 3 |
0.2%
|
|
1974 | 1 |
0.1%
|
|
1975 | 2 |
0.1%
|
|
1976 | 3 |
0.2%
|
|
1978 | 3 |
0.2%
|
|
1980 | 4 |
0.3%
|
|
1982 | 2 |
0.1%
|
|
1983 | 2 |
0.1%
|
|
1984 | 1 |
0.1%
|
|
1986 | 2 |
0.1%
|
|
1988 | 2 |
0.1%
|
|
1989 | 8 |
0.6%
|
|
1990 | 8 |
0.6%
|
|
1991 | 32 |
2.4%
|
|
1992 | 47 |
3.5%
|
|
1993 | 40 |
3%
|
|
1994 | 58 |
4.3%
|
|
1995 | 68 |
5.1%
|
|
1996 | 76 |
5.7%
|
|
1997 | 62 |
4.6%
|
|
1998 | 72 |
5.4%
|
|
1999 | 51 |
3.8%
|
|
2000 | 65 |
4.9%
|
|
2001 | 58 |
4.3%
|
|
2002 | 43 |
3.2%
|
|
2003 | 65 |
4.9%
|
|
2004 | 50 |
3.7%
|
|
2005 | 50 |
3.7%
|
|
2006 | 55 |
4.1%
|
|
2007 | 50 |
3.7%
|
|
2008 | 39 |
2.9%
|
|
2009 | 35 |
2.6%
|
|
2010 | 45 |
3.4%
|
|
2011 | 36 |
2.7%
|
|
2012 | 33 |
2.5%
|
|
2013 | 32 |
2.4%
|
|
2014 | 11 |
0.8%
|
|
2015 | 2 |
0.1%
|
|
2016 | 2 |
0.1%
|
|
2017 | 3 |
0.2%
|