| Value | Category | Cases | |
|---|---|---|---|
| 2009 | 1 |
0.9%
|
|
| 2011 | 10 |
8.7%
|
|
| 2012 | 36 |
31.3%
|
|
| 2013 | 36 |
31.3%
|
|
| 2014 | 15 |
13%
|
|
| 2015 | 6 |
5.2%
|
|
| 2016 | 1 |
0.9%
|
|
| 9998 | Don't know | 10 |
8.7%
|
| Sysmiss | 4 |