| Value | Category | Cases | |
|---|---|---|---|
| 2000 | 1 |
0.5%
|
|
| 2001 | 2 |
1.1%
|
|
| 2002 | 26 |
14.1%
|
|
| 2003 | 32 |
17.3%
|
|
| 2004 | 29 |
15.7%
|
|
| 2005 | 28 |
15.1%
|
|
| 2006 | 33 |
17.8%
|
|
| 2007 | 34 |
18.4%
|
|
| Sysmiss | 21 |