| Value | Category | Cases | |
|---|---|---|---|
| 2007 | 4 |
2.6%
|
|
| 2008 | 24 |
15.4%
|
|
| 2009 | 34 |
21.8%
|
|
| 2010 | 43 |
27.6%
|
|
| 2011 | 49 |
31.4%
|
|
| 2012 | 2 |
1.3%
|
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 472 |