| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 2 |
0.5%
|
|
| 2007 | 5 |
1.1%
|
|
| 2008 | 6 |
1.4%
|
|
| 2009 | 25 |
5.6%
|
|
| 2010 | 41 |
9.3%
|
|
| 2011 | 26 |
5.9%
|
|
| 9997 | Inconsistent (Secondary Editing) | 0 |
0%
|
| 9999 | Missing | 338 |
76.3%
|
| Sysmiss | 4384 |