| Value | Category | Cases | |
|---|---|---|---|
| 2004 | 1 |
1.5%
|
|
| 2005 | 3 |
4.5%
|
|
| 2006 | 9 |
13.6%
|
|
| 2007 | 16 |
24.2%
|
|
| 2008 | 16 |
24.2%
|
|
| 2009 | 13 |
19.7%
|
|
| 2010 | 7 |
10.6%
|
|
| 2011 | 1 |
1.5%
|
|
| Sysmiss | 2 |