| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
7.3%
|
| 1900 | 1 |
0.6%
|
|
| 1952 | 1 |
0.6%
|
|
| 1961 | 1 |
0.6%
|
|
| 1965 | 2 |
1.2%
|
|
| 1966 | 1 |
0.6%
|
|
| 1967 | 1 |
0.6%
|
|
| 1969 | 1 |
0.6%
|
|
| 1970 | 2 |
1.2%
|
|
| 1971 | 2 |
1.2%
|
|
| 1972 | 1 |
0.6%
|
|
| 1973 | 1 |
0.6%
|
|
| 1975 | 4 |
2.4%
|
|
| 1977 | 2 |
1.2%
|
|
| 1978 | 1 |
0.6%
|
|
| 1979 | 1 |
0.6%
|
|
| 1980 | 9 |
5.5%
|
|
| 1982 | 3 |
1.8%
|
|
| 1985 | 2 |
1.2%
|
|
| 1988 | 1 |
0.6%
|
|
| 1989 | 3 |
1.8%
|
|
| 1990 | 6 |
3.6%
|
|
| 1991 | 1 |
0.6%
|
|
| 1992 | 1 |
0.6%
|
|
| 1993 | 1 |
0.6%
|
|
| 1994 | 2 |
1.2%
|
|
| 1995 | 4 |
2.4%
|
|
| 1996 | 2 |
1.2%
|
|
| 1997 | 4 |
2.4%
|
|
| 1998 | 1 |
0.6%
|
|
| 1999 | 5 |
3%
|
|
| 2000 | 17 |
10.3%
|
|
| 2002 | 2 |
1.2%
|
|
| 2003 | 6 |
3.6%
|
|
| 2004 | 5 |
3%
|
|
| 2005 | 6 |
3.6%
|
|
| 2007 | 4 |
2.4%
|
|
| 2008 | 5 |
3%
|
|
| 2009 | 4 |
2.4%
|
|
| 2010 | 10 |
6.1%
|
|
| 2011 | 8 |
4.8%
|
|
| 2012 | 3 |
1.8%
|
|
| 2013 | 3 |
1.8%
|
|
| 2014 | 4 |
2.4%
|
|
| 2016 | 2 |
1.2%
|
|
| 2017 | 1 |
0.6%
|
|
| 2018 | 6 |
3.6%
|
|
| Sysmiss | 367 |