| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 1 |
0.5%
|
|
| 1992 | 1 |
0.5%
|
|
| 1993 | 1 |
0.5%
|
|
| 1996 | 2 |
1%
|
|
| 1997 | 1 |
0.5%
|
|
| 1998 | 3 |
1.4%
|
|
| 1999 | 4 |
1.9%
|
|
| 2000 | 6 |
2.9%
|
|
| 2001 | 5 |
2.4%
|
|
| 2002 | 27 |
12.9%
|
|
| 2003 | 159 |
75.7%
|
|
| Sysmiss | 7815 |