| Value | Category | Cases | |
|---|---|---|---|
| 1987 | 1 |
0.9%
|
|
| 1990 | 1 |
0.9%
|
|
| 1995 | 1 |
0.9%
|
|
| 1996 | 1 |
0.9%
|
|
| 1998 | 1 |
0.9%
|
|
| 1999 | 1 |
0.9%
|
|
| 2000 | 8 |
7.5%
|
|
| 2002 | 1 |
0.9%
|
|
| 2004 | 2 |
1.9%
|
|
| 2005 | 5 |
4.7%
|
|
| 2006 | 16 |
15.1%
|
|
| 2007 | 6 |
5.7%
|
|
| 2008 | 13 |
12.3%
|
|
| 2009 | 14 |
13.2%
|
|
| 2010 | 15 |
14.2%
|
|
| 2011 | 20 |
18.9%
|
|
| Sysmiss | 355 |