| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 381 |
11.5%
|
|
| 2005 | 532 |
16.1%
|
|
| 2006 | 680 |
20.6%
|
|
| 2007 | 727 |
22%
|
|
| 2008 | 899 |
27.2%
|
|
| 2009 | 44 |
1.3%
|
|
| 9997 | Inconsistent | 42 |
1.3%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 2774 |