| Value | Category | Cases | |
|---|---|---|---|
| 1998 | 1 |
4.8%
|
|
| 1999 | 3 |
14.3%
|
|
| 2000 | 4 |
19%
|
|
| 2001 | 10 |
47.6%
|
|
| 2002 | 3 |
14.3%
|
|
| Sysmiss | 8028 |