| Value | Category | Cases | |
|---|---|---|---|
| 2010 | 4 |
13.8%
|
|
| 2011 | 8 |
27.6%
|
|
| 2012 | 12 |
41.4%
|
|
| 2013 | 5 |
17.2%
|
|
| Sysmiss | 21 |