| Value | Category | Cases | |
|---|---|---|---|
| -9 | don't know | 40 |
5.5%
|
| -8 | does not apply | 0 |
0%
|
| -7 | refused to answer | 0 |
0%
|
| 2008 | 41 |
5.7%
|
|
| 2009 | 58 |
8%
|
|
| 2010 | 40 |
5.5%
|
|
| 2011 | 126 |
17.5%
|
|
| 2012 | 181 |
25.1%
|
|
| 2013 | 166 |
23%
|
|
| 2014 | 68 |
9.4%
|
|
| 2015 | 2 |
0.3%
|
|
| Sysmiss | 34 |