| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 16 |
0.7%
|
| 1911 | 1 |
0%
|
|
| 1914 | 1 |
0%
|
|
| 1936 | 1 |
0%
|
|
| 1940 | 1 |
0%
|
|
| 1946 | 1 |
0%
|
|
| 1952 | 2 |
0.1%
|
|
| 1955 | 3 |
0.1%
|
|
| 1956 | 1 |
0%
|
|
| 1957 | 1 |
0%
|
|
| 1960 | 1 |
0%
|
|
| 1964 | 2 |
0.1%
|
|
| 1965 | 1 |
0%
|
|
| 1966 | 2 |
0.1%
|
|
| 1967 | 1 |
0%
|
|
| 1968 | 1 |
0%
|
|
| 1969 | 3 |
0.1%
|
|
| 1970 | 3 |
0.1%
|
|
| 1971 | 1 |
0%
|
|
| 1972 | 1 |
0%
|
|
| 1973 | 1 |
0%
|
|
| 1976 | 1 |
0%
|
|
| 1979 | 2 |
0.1%
|
|
| 1980 | 1 |
0%
|
|
| 1982 | 1 |
0%
|
|
| 1983 | 2 |
0.1%
|
|
| 1984 | 4 |
0.2%
|
|
| 1985 | 7 |
0.3%
|
|
| 1986 | 5 |
0.2%
|
|
| 1987 | 4 |
0.2%
|
|
| 1988 | 5 |
0.2%
|
|
| 1989 | 5 |
0.2%
|
|
| 1990 | 5 |
0.2%
|
|
| 1991 | 3 |
0.1%
|
|
| 1992 | 8 |
0.4%
|
|
| 1993 | 21 |
1%
|
|
| 1994 | 13 |
0.6%
|
|
| 1995 | 19 |
0.9%
|
|
| 1996 | 27 |
1.2%
|
|
| 1997 | 28 |
1.3%
|
|
| 1998 | 29 |
1.3%
|
|
| 1999 | 36 |
1.6%
|
|
| 2000 | 46 |
2.1%
|
|
| 2001 | 39 |
1.8%
|
|
| 2002 | 57 |
2.6%
|
|
| 2003 | 81 |
3.7%
|
|
| 2004 | 76 |
3.5%
|
|
| 2005 | 67 |
3.1%
|
|
| 2006 | 85 |
3.9%
|
|
| 2007 | 64 |
2.9%
|
|
| 2008 | 55 |
2.5%
|
|
| 2009 | 58 |
2.6%
|
|
| 2010 | 69 |
3.2%
|
|
| 2011 | 67 |
3.1%
|
|
| 2012 | 69 |
3.2%
|
|
| 2013 | 80 |
3.7%
|
|
| 2014 | 80 |
3.7%
|
|
| 2015 | 98 |
4.5%
|
|
| 2016 | 98 |
4.5%
|
|
| 2017 | 126 |
5.8%
|
|
| 2018 | 109 |
5%
|
|
| 2019 | 114 |
5.2%
|
|
| 2020 | 108 |
4.9%
|
|
| 2021 | 100 |
4.6%
|
|
| 2022 | 84 |
3.8%
|
|
| 2023 | 86 |
3.9%
|
|
| 2024 | 2 |
0.1%
|