| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
5.9%
|
| 1968 | 1 |
1.5%
|
|
| 1970 | 1 |
1.5%
|
|
| 1974 | 1 |
1.5%
|
|
| 1977 | 1 |
1.5%
|
|
| 1978 | 1 |
1.5%
|
|
| 1979 | 1 |
1.5%
|
|
| 1981 | 1 |
1.5%
|
|
| 1984 | 1 |
1.5%
|
|
| 1989 | 1 |
1.5%
|
|
| 1990 | 2 |
2.9%
|
|
| 1991 | 3 |
4.4%
|
|
| 1992 | 3 |
4.4%
|
|
| 1993 | 1 |
1.5%
|
|
| 1995 | 4 |
5.9%
|
|
| 1996 | 1 |
1.5%
|
|
| 1997 | 1 |
1.5%
|
|
| 1999 | 1 |
1.5%
|
|
| 2000 | 1 |
1.5%
|
|
| 2001 | 2 |
2.9%
|
|
| 2002 | 3 |
4.4%
|
|
| 2004 | 2 |
2.9%
|
|
| 2005 | 2 |
2.9%
|
|
| 2006 | 6 |
8.8%
|
|
| 2007 | 1 |
1.5%
|
|
| 2009 | 1 |
1.5%
|
|
| 2010 | 1 |
1.5%
|
|
| 2011 | 1 |
1.5%
|
|
| 2012 | 2 |
2.9%
|
|
| 2014 | 2 |
2.9%
|
|
| 2015 | 1 |
1.5%
|
|
| 2016 | 4 |
5.9%
|
|
| 2019 | 2 |
2.9%
|
|
| 2020 | 1 |
1.5%
|
|
| 2021 | 2 |
2.9%
|
|
| 2022 | 4 |
5.9%
|
|
| 2023 | 1 |
1.5%
|
|
| Sysmiss | 173 |