| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 3 |
0.7%
|
|
| 1997 | 18 |
4.3%
|
|
| 1998 | 19 |
4.5%
|
|
| 1999 | 50 |
11.9%
|
|
| 2000 | 56 |
13.4%
|
|
| 2001 | 138 |
32.9%
|
|
| 2002 | 135 |
32.2%
|
|
| Sysmiss | 798 |