| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 7 |
2.1%
|
|
| 1996 | 124 |
37.8%
|
|
| 1997 | 105 |
32%
|
|
| 1998 | 65 |
19.8%
|
|
| 1999 | 17 |
5.2%
|
|
| 2000 | 10 |
3%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 6427 |