| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 302 |
15.9%
|
|
| 2008 | 480 |
25.3%
|
|
| 2009 | 442 |
23.3%
|
|
| 2010 | 422 |
22.2%
|
|
| 2011 | 251 |
13.2%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 435 |