| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 1 |
0.3%
|
|
| 1998 | 1 |
0.3%
|
|
| 2000 | 2 |
0.7%
|
|
| 2001 | 3 |
1%
|
|
| 2002 | 5 |
1.7%
|
|
| 2003 | 8 |
2.8%
|
|
| 2004 | 17 |
5.9%
|
|
| 2005 | 16 |
5.6%
|
|
| 2006 | 41 |
14.3%
|
|
| 2007 | 120 |
41.8%
|
|
| 2008 | 73 |
25.4%
|
|
| Sysmiss | 473 |