| Value | Category | Cases | |
|---|---|---|---|
| 2005 | 1 |
2.5%
|
|
| 2006 | 3 |
7.5%
|
|
| 2007 | 5 |
12.5%
|
|
| 2008 | 11 |
27.5%
|
|
| 2009 | 11 |
27.5%
|
|
| 2010 | 9 |
22.5%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 44 |