| Value | Category | Cases | |
|---|---|---|---|
| 1975 | 1 |
0.2%
|
|
| 1998 | 1 |
0.2%
|
|
| 2002 | 3 |
0.6%
|
|
| 2003 | 3 |
0.6%
|
|
| 2004 | 1 |
0.2%
|
|
| 2005 | 2 |
0.4%
|
|
| 2006 | 3 |
0.6%
|
|
| 2007 | 3 |
0.6%
|
|
| 2008 | 5 |
1%
|
|
| 2009 | 9 |
1.7%
|
|
| 2010 | 19 |
3.7%
|
|
| 2011 | 23 |
4.4%
|
|
| 2012 | 42 |
8.1%
|
|
| 2013 | 60 |
11.6%
|
|
| 2014 | 161 |
31%
|
|
| 2015 | 173 |
33.3%
|
|
| 2016 | 9 |
1.7%
|
|
| 9998 | don't know/don't remember | 1 |
0.2%
|
| Sysmiss | 12396 |