| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 1 |
3%
|
|
| 2008 | 5 |
15.2%
|
|
| 2009 | 8 |
24.2%
|
|
| 2010 | 19 |
57.6%
|
|
| Sysmiss | 277 |