| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 11 |
3%
|
|
| 2005 | 60 |
16.3%
|
|
| 2006 | 76 |
20.7%
|
|
| 2007 | 117 |
31.9%
|
|
| 2008 | 100 |
27.2%
|
|
| 2009 | 1 |
0.3%
|
|
| 9997 | Inconsistent | 2 |
0.5%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 5712 |