| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 275 |
16.2%
|
|
| 1997 | 410 |
24.2%
|
|
| 1998 | 406 |
24%
|
|
| 1999 | 402 |
23.7%
|
|
| 2000 | 201 |
11.9%
|
|
| 9997 | Missing | 0 |
0%
|
| Sysmiss | 927 |