| Value | Category | Cases | |
|---|---|---|---|
| 1988 | 5 |
0.3%
|
|
| 1989 | 12 |
0.7%
|
|
| 1990 | 35 |
2%
|
|
| 1991 | 28 |
1.6%
|
|
| 1992 | 28 |
1.6%
|
|
| 1993 | 27 |
1.6%
|
|
| 1994 | 25 |
1.5%
|
|
| 1995 | 56 |
3.3%
|
|
| 1996 | 75 |
4.4%
|
|
| 1997 | 71 |
4.2%
|
|
| 1998 | 69 |
4%
|
|
| 1999 | 88 |
5.1%
|
|
| 2000 | 129 |
7.5%
|
|
| 2001 | 146 |
8.5%
|
|
| 2002 | 173 |
10.1%
|
|
| 2003 | 197 |
11.5%
|
|
| 2004 | 253 |
14.8%
|
|
| 2005 | 207 |
12.1%
|
|
| 2006 | 70 |
4.1%
|
|
| 2007 | 15 |
0.9%
|
|
| 2008 | 1 |
0.1%
|