| Value | Category | Cases | |
|---|---|---|---|
| 1994 | 6 |
2.3%
|
|
| 1995 | 3 |
1.1%
|
|
| 1996 | 6 |
2.3%
|
|
| 1997 | 14 |
5.3%
|
|
| 1998 | 70 |
26.3%
|
|
| 1999 | 94 |
35.3%
|
|
| 2000 | 73 |
27.4%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 15719 |