| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 23 |
1.5%
|
|
| 2005 | 150 |
10%
|
|
| 2006 | 228 |
15.2%
|
|
| 2007 | 425 |
28.3%
|
|
| 2008 | 610 |
40.6%
|
|
| 2009 | 38 |
2.5%
|
|
| 9997 | Inconsistent | 30 |
2%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 6940 |