| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 59 |
3%
|
|
| 2005 | 112 |
5.8%
|
|
| 2006 | 129 |
6.7%
|
|
| 2007 | 126 |
6.5%
|
|
| 2008 | 66 |
3.4%
|
|
| 9999 | Missing | 1443 |
74.6%
|
| Sysmiss | 12309 |