| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 18 |
12.9%
|
|
| 2008 | 30 |
21.6%
|
|
| 2009 | 20 |
14.4%
|
|
| 2010 | 32 |
23%
|
|
| 2011 | 38 |
27.3%
|
|
| 2012 | 1 |
0.7%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 621 |