| Value | Category | Cases | |
|---|---|---|---|
| 1988 | 1 |
3.8%
|
|
| 1989 | 1 |
3.8%
|
|
| 1990 | 1 |
3.8%
|
|
| 1991 | 3 |
11.5%
|
|
| 1992 | 2 |
7.7%
|
|
| 1993 | 1 |
3.8%
|
|
| 1994 | 2 |
7.7%
|
|
| 1995 | 3 |
11.5%
|
|
| 1996 | 1 |
3.8%
|
|
| 1997 | 3 |
11.5%
|
|
| 1998 | 2 |
7.7%
|
|
| 1999 | 2 |
7.7%
|
|
| 2001 | 1 |
3.8%
|
|
| 2002 | 1 |
3.8%
|
|
| 2003 | 2 |
7.7%
|
|
| Sysmiss | 2991 |