| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 4 |
3.5%
|
|
| 2007 | 21 |
18.6%
|
|
| 2008 | 35 |
31%
|
|
| 2009 | 15 |
13.3%
|
|
| 2010 | 38 |
33.6%
|
|
| Sysmiss | 97 |