| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 171 |
21.8%
|
|
| 2005 | 254 |
32.4%
|
|
| 2006 | 238 |
30.4%
|
|
| 2007 | 89 |
11.4%
|
|
| 2008 | 17 |
2.2%
|
|
| 9997 | Inconsistent | 15 |
1.9%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 7660 |