| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 2 |
0.8%
|
|
| 2007 | 11 |
4.6%
|
|
| 2008 | 5 |
2.1%
|
|
| 2009 | 30 |
12.6%
|
|
| 2010 | 64 |
26.8%
|
|
| 2011 | 59 |
24.7%
|
|
| 9997 | Inconsistent (Secondary Editing) | 1 |
0.4%
|
| 9999 | Missing | 67 |
28%
|
| Sysmiss | 4588 |