| Value | Category | Cases | |
|---|---|---|---|
| 1989 | 1 |
1%
|
|
| 1993 | 9 |
9.4%
|
|
| 1994 | 16 |
16.7%
|
|
| 1995 | 11 |
11.5%
|
|
| 1996 | 24 |
25%
|
|
| 1997 | 34 |
35.4%
|
|
| 1998 | 1 |
1%
|
|
| Sysmiss | 19796 |