| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 6 |
2.1%
|
|
| 2005 | 70 |
24.6%
|
|
| 2006 | 67 |
23.6%
|
|
| 2007 | 75 |
26.4%
|
|
| 2008 | 60 |
21.1%
|
|
| 2009 | 1 |
0.4%
|
|
| 9997 | Inconsistent | 5 |
1.8%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 8160 |