| Value | Category | Cases | |
|---|---|---|---|
| 1999 | 2 |
4.2%
|
|
| 2000 | 1 |
2.1%
|
|
| 2001 | 15 |
31.3%
|
|
| 2002 | 30 |
62.5%
|
|
| Sysmiss | 8062 |