Value | Category | Cases | |
---|---|---|---|
-9 | Don't know (spontaneous) | 24 |
8.4%
|
1950 | 2 |
0.7%
|
|
1960 | 3 |
1%
|
|
1968 | 3 |
1%
|
|
1970 | 5 |
1.7%
|
|
1971 | 1 |
0.3%
|
|
1972 | 2 |
0.7%
|
|
1973 | 1 |
0.3%
|
|
1975 | 4 |
1.4%
|
|
1976 | 2 |
0.7%
|
|
1979 | 3 |
1%
|
|
1980 | 11 |
3.8%
|
|
1983 | 1 |
0.3%
|
|
1984 | 1 |
0.3%
|
|
1985 | 7 |
2.4%
|
|
1986 | 1 |
0.3%
|
|
1987 | 1 |
0.3%
|
|
1988 | 1 |
0.3%
|
|
1989 | 1 |
0.3%
|
|
1990 | 24 |
8.4%
|
|
1991 | 3 |
1%
|
|
1992 | 4 |
1.4%
|
|
1993 | 2 |
0.7%
|
|
1994 | 5 |
1.7%
|
|
1995 | 10 |
3.5%
|
|
1996 | 4 |
1.4%
|
|
1997 | 3 |
1%
|
|
1998 | 4 |
1.4%
|
|
1999 | 3 |
1%
|
|
2000 | 32 |
11.1%
|
|
2001 | 6 |
2.1%
|
|
2002 | 4 |
1.4%
|
|
2003 | 5 |
1.7%
|
|
2004 | 2 |
0.7%
|
|
2005 | 12 |
4.2%
|
|
2006 | 6 |
2.1%
|
|
2007 | 6 |
2.1%
|
|
2008 | 7 |
2.4%
|
|
2009 | 4 |
1.4%
|
|
2010 | 16 |
5.6%
|
|
2011 | 7 |
2.4%
|
|
2012 | 8 |
2.8%
|
|
2013 | 6 |
2.1%
|
|
2014 | 4 |
1.4%
|
|
2015 | 14 |
4.9%
|
|
2016 | 7 |
2.4%
|
|
2017 | 4 |
1.4%
|
|
2018 | 1 |
0.3%
|
|
Sysmiss | 473 |