| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 91 |
6.6%
|
|
| 1997 | 338 |
24.3%
|
|
| 1998 | 408 |
29.4%
|
|
| 1999 | 381 |
27.4%
|
|
| 2000 | 171 |
12.3%
|
|
| 9997 | Missing | 0 |
0%
|
| Sysmiss | 1232 |