| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 3 |
37.5%
|
|
| 2007 | 1 |
12.5%
|
|
| 2008 | 2 |
25%
|
|
| 2009 | 2 |
25%
|
|
| Sysmiss | 632 |