| Value | Category | Cases | |
|---|---|---|---|
| 1991 | 1 |
0.5%
|
|
| 1992 | 1 |
0.5%
|
|
| 1993 | 1 |
0.5%
|
|
| 1994 | 1 |
0.5%
|
|
| 1995 | 2 |
0.9%
|
|
| 1998 | 1 |
0.5%
|
|
| 2000 | 4 |
1.8%
|
|
| 2001 | 36 |
16.6%
|
|
| 2002 | 169 |
77.9%
|
|
| 2003 | 1 |
0.5%
|
|
| Sysmiss | 7893 |