| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 1 |
0.1%
|
|
| 1993 | 261 |
20.2%
|
|
| 1994 | 585 |
45.2%
|
|
| 1995 | 232 |
17.9%
|
|
| 1996 | 151 |
11.7%
|
|
| 1997 | 62 |
4.8%
|
|
| 1998 | 3 |
0.2%
|
|
| Sysmiss | 1 |