| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 142 |
6%
|
| 1988 | 1988 | 1 |
0%
|
| 1989 | 1989 | 1 |
0%
|
| 1990 | 1990 | 0 |
0%
|
| 1991 | 1991 | 1 |
0%
|
| 1992 | 1992 | 3 |
0.1%
|
| 1993 | 1993 | 2 |
0.1%
|
| 1994 | 1994 | 6 |
0.3%
|
| 1995 | 1995 | 6 |
0.3%
|
| 1996 | 1996 | 11 |
0.5%
|
| 1997 | 1997 | 10 |
0.4%
|
| 1998 | 1998 | 17 |
0.7%
|
| 1999 | 1999 | 27 |
1.1%
|
| 2000 | 2000 | 37 |
1.6%
|
| 2001 | 2001 | 37 |
1.6%
|
| 2002 | 2002 | 44 |
1.9%
|
| 2003 | 2003 | 67 |
2.8%
|
| 2004 | 2004 | 64 |
2.7%
|
| 2005 | 2005 | 91 |
3.9%
|
| 2006 | 2006 | 104 |
4.4%
|
| 2007 | 2007 | 118 |
5%
|
| 2008 | 2008 | 116 |
4.9%
|
| 2009 | 2009 | 127 |
5.4%
|
| 2010 | 2010 | 175 |
7.4%
|
| 2011 | 2011 | 187 |
7.9%
|
| 2012 | 2012 | 182 |
7.7%
|
| 2013 | 2013 | 208 |
8.8%
|
| 2014 | 2014 | 231 |
9.8%
|
| 2015 | 2015 | 247 |
10.5%
|
| 2016 | 2016 | 98 |
4.2%
|
| Sysmiss | 4801 |