| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 2 |
7.1%
|
|
| 1997 | 1 |
3.6%
|
|
| 1999 | 14 |
50%
|
|
| 2000 | 11 |
39.3%
|
|
| Sysmiss | 15957 |