| Value | Category | Cases | |
|---|---|---|---|
| -9 | do not know | 5 |
4.4%
|
| 2001 | 1 |
0.9%
|
|
| 2004 | 1 |
0.9%
|
|
| 2005 | 1 |
0.9%
|
|
| 2006 | 2 |
1.8%
|
|
| 2007 | 3 |
2.7%
|
|
| 2008 | 4 |
3.5%
|
|
| 2009 | 13 |
11.5%
|
|
| 2010 | 38 |
33.6%
|
|
| 2011 | 45 |
39.8%
|
|
| Sysmiss | 128 |