| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 8 |
0.4%
|
|
| 2007 | 402 |
20.7%
|
|
| 2008 | 469 |
24.1%
|
|
| 2009 | 442 |
22.7%
|
|
| 2010 | 443 |
22.8%
|
|
| 2011 | 182 |
9.4%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 386 |