| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 1 |
5%
|
|
| 1994 | 1 |
5%
|
|
| 1995 | 8 |
40%
|
|
| 1996 | 3 |
15%
|
|
| 1997 | 7 |
35%
|
|
| Sysmiss | 293 |