| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 7 |
2.1%
|
|
| 1996 | 120 |
36.7%
|
|
| 1997 | 106 |
32.4%
|
|
| 1998 | 66 |
20.2%
|
|
| 1999 | 18 |
5.5%
|
|
| 2000 | 10 |
3.1%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 6428 |