| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 7 |
0.6%
|
|
| 2007 | 179 |
16.1%
|
|
| 2008 | 214 |
19.2%
|
|
| 2009 | 268 |
24.1%
|
|
| 2010 | 314 |
28.2%
|
|
| 2011 | 130 |
11.7%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 810 |