| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 1 |
7.7%
|
|
| 1992 | 1 |
7.7%
|
|
| 1993 | 4 |
30.8%
|
|
| 1994 | 2 |
15.4%
|
|
| 1995 | 2 |
15.4%
|
|
| 1996 | 1 |
7.7%
|
|
| 1997 | 2 |
15.4%
|