| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 1 |
2.4%
|
|
| 2005 | 21 |
50%
|
|
| 2006 | 19 |
45.2%
|
|
| 2007 | 1 |
2.4%
|
|
| Sysmiss | 957 |