| Value | Category | Cases | |
|---|---|---|---|
| 1999 | 2 |
0.5%
|
|
| 2000 | 2 |
0.5%
|
|
| 2004 | 1 |
0.2%
|
|
| 2006 | 4 |
0.9%
|
|
| 2007 | 3 |
0.7%
|
|
| 2008 | 53 |
12.3%
|
|
| 2009 | 173 |
40.1%
|
|
| 2010 | 169 |
39.2%
|
|
| 2011 | 24 |
5.6%
|
|
| Sysmiss | 30 |