| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 5 |
0.3%
|
|
| 2008 | 326 |
20.7%
|
|
| 2009 | 444 |
28.2%
|
|
| 2010 | 408 |
25.9%
|
|
| 2011 | 389 |
24.7%
|
|
| 2012 | 2 |
0.1%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 758 |