| Value | Category | Cases | |
|---|---|---|---|
| 2002 | 2 |
0.5%
|
|
| 2007 | 16 |
4.3%
|
|
| 2008 | 267 |
71.6%
|
|
| 2009 | 88 |
23.6%
|
|
| Sysmiss | 112 |