| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 1 |
1.1%
|
|
| 1998 | 1 |
1.1%
|
|
| 1999 | 2 |
2.2%
|
|
| 2000 | 4 |
4.3%
|
|
| 2001 | 8 |
8.7%
|
|
| 2002 | 8 |
8.7%
|
|
| 2003 | 4 |
4.3%
|
|
| 2004 | 19 |
20.7%
|
|
| 2005 | 16 |
17.4%
|
|
| 2006 | 18 |
19.6%
|
|
| 2007 | 10 |
10.9%
|
|
| 9998 | 1 |
1.1%
|