| Value | Category | Cases | |
|---|---|---|---|
| 2009 | 2 |
4.3%
|
|
| 2010 | 6 |
12.8%
|
|
| 2011 | 18 |
38.3%
|
|
| 2012 | 17 |
36.2%
|
|
| 2013 | 4 |
8.5%
|
|
| Sysmiss | 3 |