| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 9 |
7.1%
|
|
| 2008 | 19 |
15.1%
|
|
| 2009 | 18 |
14.3%
|
|
| 2010 | 42 |
33.3%
|
|
| 2011 | 38 |
30.2%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 502 |