| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 327 |
10.5%
|
|
| 2005 | 508 |
16.3%
|
|
| 2006 | 648 |
20.8%
|
|
| 2007 | 699 |
22.4%
|
|
| 2008 | 846 |
27.1%
|
|
| 2009 | 48 |
1.5%
|
|
| 9997 | Inconsistent | 43 |
1.4%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 2960 |