| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 8 |
16%
|
|
| 2007 | 7 |
14%
|
|
| 2008 | 15 |
30%
|
|
| 2009 | 11 |
22%
|
|
| 2010 | 9 |
18%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 354 |