| Value | Category | Cases | |
|---|---|---|---|
| 1980 | 1 |
1.8%
|
|
| 1990 | 1 |
1.8%
|
|
| 1998 | 1 |
1.8%
|
|
| 2000 | 3 |
5.5%
|
|
| 2002 | 1 |
1.8%
|
|
| 2003 | 2 |
3.6%
|
|
| 2004 | 1 |
1.8%
|
|
| 2005 | 5 |
9.1%
|
|
| 2006 | 3 |
5.5%
|
|
| 2007 | 4 |
7.3%
|
|
| 2008 | 3 |
5.5%
|
|
| 2009 | 1 |
1.8%
|
|
| 2010 | 6 |
10.9%
|
|
| 2011 | 10 |
18.2%
|
|
| 2012 | 9 |
16.4%
|
|
| 2013 | 4 |
7.3%
|
|
| Sysmiss | 845 |