| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 9 |
1.1%
|
|
| 2005 | 52 |
6.4%
|
|
| 2006 | 97 |
11.9%
|
|
| 2007 | 215 |
26.5%
|
|
| 2008 | 406 |
50%
|
|
| 2009 | 23 |
2.8%
|
|
| 9997 | Inconsistent | 10 |
1.2%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 7632 |