| Value | Category | Cases | |
|---|---|---|---|
| 1987 | 2 |
1.6%
|
|
| 1992 | 1 |
0.8%
|
|
| 1995 | 1 |
0.8%
|
|
| 1996 | 3 |
2.4%
|
|
| 1997 | 7 |
5.5%
|
|
| 1998 | 6 |
4.7%
|
|
| 1999 | 1 |
0.8%
|
|
| 2000 | 9 |
7.1%
|
|
| 2001 | 8 |
6.3%
|
|
| 2002 | 15 |
11.8%
|
|
| 2003 | 10 |
7.9%
|
|
| 2004 | 11 |
8.7%
|
|
| 2005 | 20 |
15.7%
|
|
| 2006 | 33 |
26%
|
|
| Sysmiss | 306 |