| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 1 |
0.7%
|
|
| 1996 | 1 |
0.7%
|
|
| 2000 | 7 |
4.9%
|
|
| 2002 | 3 |
2.1%
|
|
| 2003 | 1 |
0.7%
|
|
| 2004 | 2 |
1.4%
|
|
| 2006 | 10 |
6.9%
|
|
| 2007 | 17 |
11.8%
|
|
| 2008 | 23 |
16%
|
|
| 2009 | 14 |
9.7%
|
|
| 2010 | 28 |
19.4%
|
|
| 2011 | 12 |
8.3%
|
|
| 2012 | 25 |
17.4%
|
|
| Sysmiss | 319 |