| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 235 |
3.1%
|
|
| 2005 | 821 |
10.9%
|
|
| 2006 | 879 |
11.7%
|
|
| 2007 | 931 |
12.4%
|
|
| 2008 | 1013 |
13.5%
|
|
| 2009 | 401 |
5.3%
|
|
| 9998 | dk | 2 |
0%
|
| 9999 | missing | 468 |
6.2%
|
| Sysmiss | 2749 |
36.7%
|