| Value | Category | Cases | |
|---|---|---|---|
| -9 | do not know | 0 |
0%
|
| 2005 | 1 |
2.6%
|
|
| 2007 | 2 |
5.3%
|
|
| 2008 | 4 |
10.5%
|
|
| 2009 | 10 |
26.3%
|
|
| 2010 | 10 |
26.3%
|
|
| 2011 | 11 |
28.9%
|
|
| Sysmiss | 110 |