| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 80 |
24.3%
|
|
| 1997 | 116 |
35.3%
|
|
| 1998 | 83 |
25.2%
|
|
| 1999 | 37 |
11.2%
|
|
| 2000 | 13 |
4%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 6426 |