| Value | Category | Cases | |
|---|---|---|---|
| 2003 | 1 |
1.5%
|
|
| 2004 | 37 |
55.2%
|
|
| 2005 | 20 |
29.9%
|
|
| 2006 | 5 |
7.5%
|
|
| 2007 | 1 |
1.5%
|
|
| 9997 | Inconsistent | 3 |
4.5%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 8377 |