| Value | Category | Cases | |
|---|---|---|---|
| 2008 | 7 |
24.1%
|
|
| 2013 | 12 |
41.4%
|
|
| 2014 | 8 |
27.6%
|
|
| 2015 | 2 |
6.9%
|
|
| 9998 | don't know | 0 |
0%
|
| Sysmiss | 62564 |