| Value | Category | Cases | |
|---|---|---|---|
| 1988 | 2 |
0.1%
|
|
| 1989 | 7 |
0.5%
|
|
| 1990 | 38 |
2.5%
|
|
| 1991 | 36 |
2.3%
|
|
| 1992 | 42 |
2.7%
|
|
| 1993 | 48 |
3.1%
|
|
| 1994 | 55 |
3.6%
|
|
| 1995 | 54 |
3.5%
|
|
| 1996 | 71 |
4.6%
|
|
| 1997 | 66 |
4.3%
|
|
| 1998 | 86 |
5.6%
|
|
| 1999 | 116 |
7.5%
|
|
| 2000 | 131 |
8.5%
|
|
| 2001 | 107 |
7%
|
|
| 2002 | 132 |
8.6%
|
|
| 2003 | 142 |
9.2%
|
|
| 2004 | 155 |
10.1%
|
|
| 2005 | 223 |
14.5%
|
|
| 2006 | 22 |
1.4%
|
|
| 2007 | 4 |
0.3%
|
|
| 2008 | 2 |
0.1%
|