| Value | Category | Cases | |
|---|---|---|---|
| 1985 | 1 |
0.3%
|
|
| 1990 | 1 |
0.3%
|
|
| 1992 | 67 |
22%
|
|
| 1993 | 7 |
2.3%
|
|
| 1994 | 2 |
0.7%
|
|
| 1995 | 122 |
40%
|
|
| 1996 | 86 |
28.2%
|
|
| 1997 | 19 |
6.2%
|
|
| Sysmiss | 5 |