| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 9 |
17.3%
|
|
| 2005 | 13 |
25%
|
|
| 2006 | 15 |
28.8%
|
|
| 2007 | 8 |
15.4%
|
|
| 2008 | 7 |
13.5%
|
|
| 9997 | Inconsistent | 0 |
0%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 8392 |