| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 7 |
17.1%
|
|
| 2005 | 15 |
36.6%
|
|
| 2006 | 8 |
19.5%
|
|
| 2007 | 6 |
14.6%
|
|
| 2008 | 4 |
9.8%
|
|
| 9997 | Inconsistent | 1 |
2.4%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 8403 |