| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 1 |
2.2%
|
|
| 2002 | 2 |
4.4%
|
|
| 2004 | 2 |
4.4%
|
|
| 2005 | 3 |
6.7%
|
|
| 2006 | 4 |
8.9%
|
|
| 2007 | 7 |
15.6%
|
|
| 2008 | 3 |
6.7%
|
|
| 2009 | 2 |
4.4%
|
|
| 2010 | 5 |
11.1%
|
|
| 2011 | 5 |
11.1%
|
|
| 2012 | 9 |
20%
|
|
| 9998 | Don't know | 2 |
4.4%
|
| Sysmiss | 1494 |