| Value | Category | Cases | |
|---|---|---|---|
| 1987 | 1 |
0.9%
|
|
| 1990 | 1 |
0.9%
|
|
| 1992 | 1 |
0.9%
|
|
| 1993 | 1 |
0.9%
|
|
| 1994 | 1 |
0.9%
|
|
| 1996 | 1 |
0.9%
|
|
| 1998 | 3 |
2.7%
|
|
| 2000 | 15 |
13.5%
|
|
| 2001 | 1 |
0.9%
|
|
| 2002 | 2 |
1.8%
|
|
| 2003 | 4 |
3.6%
|
|
| 2004 | 8 |
7.2%
|
|
| 2005 | 18 |
16.2%
|
|
| 2006 | 21 |
18.9%
|
|
| 2007 | 9 |
8.1%
|
|
| 2008 | 22 |
19.8%
|
|
| 9999 | 2 |
1.8%
|
|
| Sysmiss | 335 |