| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 1 |
2.2%
|
|
| 1999 | 3 |
6.5%
|
|
| 2000 | 1 |
2.2%
|
|
| 2002 | 3 |
6.5%
|
|
| 2003 | 8 |
17.4%
|
|
| 2004 | 8 |
17.4%
|
|
| 2005 | 12 |
26.1%
|
|
| 2006 | 9 |
19.6%
|
|
| 2007 | 1 |
2.2%
|
|
| Sysmiss | 876 |