| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 22 |
1.9%
|
|
| 2005 | 137 |
12%
|
|
| 2006 | 172 |
15.1%
|
|
| 2007 | 297 |
26.1%
|
|
| 2008 | 470 |
41.3%
|
|
| 2009 | 24 |
2.1%
|
|
| 9997 | Inconsistent | 16 |
1.4%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 4941 |