| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 183 |
13.7%
|
|
| 1998 | 296 |
22.1%
|
|
| 1999 | 263 |
19.6%
|
|
| 2000 | 253 |
18.9%
|
|
| 2001 | 265 |
19.8%
|
|
| 2002 | 79 |
5.9%
|
|
| Sysmiss | 1 |