| Value | Category | Cases | |
|---|---|---|---|
| 1988 | 1 |
1.5%
|
|
| 1990 | 3 |
4.4%
|
|
| 1993 | 2 |
2.9%
|
|
| 1995 | 1 |
1.5%
|
|
| 1999 | 1 |
1.5%
|
|
| 2000 | 4 |
5.9%
|
|
| 2003 | 2 |
2.9%
|
|
| 2004 | 2 |
2.9%
|
|
| 2005 | 2 |
2.9%
|
|
| 2006 | 10 |
14.7%
|
|
| 2007 | 1 |
1.5%
|
|
| 2008 | 7 |
10.3%
|
|
| 2009 | 9 |
13.2%
|
|
| 2010 | 14 |
20.6%
|
|
| 2011 | 9 |
13.2%
|
|
| Sysmiss | 393 |