| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 1 |
5%
|
|
| 1992 | 1 |
5%
|
|
| 1993 | 1 |
5%
|
|
| 1994 | 7 |
35%
|
|
| 1995 | 4 |
20%
|
|
| 1996 | 4 |
20%
|
|
| 1997 | 2 |
10%
|
|
| Sysmiss | 11 |