| Value | Category | Cases | |
|---|---|---|---|
| 1994 | 5 |
2.4%
|
|
| 1995 | 1 |
0.5%
|
|
| 1996 | 5 |
2.4%
|
|
| 1997 | 11 |
5.3%
|
|
| 1998 | 49 |
23.4%
|
|
| 1999 | 80 |
38.3%
|
|
| 2000 | 58 |
27.8%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 12027 |