| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 5 |
3.9%
|
|
| 2005 | 11 |
8.6%
|
|
| 2006 | 22 |
17.2%
|
|
| 2007 | 26 |
20.3%
|
|
| 2008 | 58 |
45.3%
|
|
| 2009 | 3 |
2.3%
|
|
| 9997 | Inconsistent | 3 |
2.3%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 8316 |