| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 53 |
48.2%
|
|
| 2005 | 35 |
31.8%
|
|
| 2006 | 13 |
11.8%
|
|
| 2007 | 5 |
4.5%
|
|
| 9997 | Inconsistent | 4 |
3.6%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 8334 |