| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 236 |
12.7%
|
|
| 2008 | 471 |
25.4%
|
|
| 2009 | 444 |
23.9%
|
|
| 2010 | 416 |
22.4%
|
|
| 2011 | 283 |
15.3%
|
|
| 2012 | 4 |
0.2%
|
|
| 9999 | Missing | 1 |
0.1%
|
| Sysmiss | 477 |