| Value | Category | Cases | |
|---|---|---|---|
| 2003 | 4 |
5.6%
|
|
| 2004 | 22 |
31%
|
|
| 2005 | 21 |
29.6%
|
|
| 2006 | 24 |
33.8%
|
|
| Sysmiss | 18395 |