| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 8 |
2.2%
|
| 1988 | 1988 | 0 |
0%
|
| 1989 | 1989 | 0 |
0%
|
| 1990 | 1990 | 0 |
0%
|
| 1991 | 1991 | 0 |
0%
|
| 1992 | 1992 | 0 |
0%
|
| 1993 | 1993 | 0 |
0%
|
| 1994 | 1994 | 0 |
0%
|
| 1995 | 1995 | 1 |
0.3%
|
| 1996 | 1996 | 1 |
0.3%
|
| 1997 | 1997 | 0 |
0%
|
| 1998 | 1998 | 3 |
0.8%
|
| 1999 | 1999 | 1 |
0.3%
|
| 2000 | 2000 | 1 |
0.3%
|
| 2001 | 2001 | 2 |
0.6%
|
| 2002 | 2002 | 1 |
0.3%
|
| 2003 | 2003 | 5 |
1.4%
|
| 2004 | 2004 | 2 |
0.6%
|
| 2005 | 2005 | 2 |
0.6%
|
| 2006 | 2006 | 2 |
0.6%
|
| 2007 | 2007 | 6 |
1.7%
|
| 2008 | 2008 | 14 |
3.9%
|
| 2009 | 2009 | 14 |
3.9%
|
| 2010 | 2010 | 17 |
4.7%
|
| 2011 | 2011 | 26 |
7.2%
|
| 2012 | 2012 | 26 |
7.2%
|
| 2013 | 2013 | 31 |
8.6%
|
| 2014 | 2014 | 52 |
14.4%
|
| 2015 | 2015 | 97 |
26.9%
|
| 2016 | 2016 | 48 |
13.3%
|
| Sysmiss | 6801 |