| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 254 |
8.9%
|
|
| 2005 | 489 |
17.2%
|
|
| 2006 | 575 |
20.3%
|
|
| 2007 | 675 |
23.8%
|
|
| 2008 | 755 |
26.6%
|
|
| 2009 | 47 |
1.7%
|
|
| 9997 | Inconsistent | 43 |
1.5%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 3241 |