| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 222 |
12.2%
|
|
| 2008 | 499 |
27.3%
|
|
| 2009 | 444 |
24.3%
|
|
| 2010 | 394 |
21.6%
|
|
| 2011 | 267 |
14.6%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 506 |