| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 1 |
2.6%
|
|
| 2000 | 3 |
7.7%
|
|
| 2004 | 2 |
5.1%
|
|
| 2005 | 2 |
5.1%
|
|
| 2006 | 5 |
12.8%
|
|
| 2007 | 3 |
7.7%
|
|
| 2008 | 4 |
10.3%
|
|
| 2009 | 6 |
15.4%
|
|
| 2010 | 4 |
10.3%
|
|
| 2011 | 9 |
23.1%
|
|
| Sysmiss | 636 |