| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 81 |
13.5%
|
|
| 1998 | 133 |
22.2%
|
|
| 1999 | 129 |
21.5%
|
|
| 2000 | 111 |
18.5%
|
|
| 2001 | 111 |
18.5%
|
|
| 2002 | 34 |
5.7%
|
|
| Sysmiss | 7374 |