| Value | Category | Cases | |
|---|---|---|---|
| 1998 | 3 |
1%
|
|
| 1999 | 4 |
1.4%
|
|
| 2000 | 7 |
2.4%
|
|
| 2001 | 6 |
2%
|
|
| 2002 | 235 |
79.7%
|
|
| 2003 | 40 |
13.6%
|
|
| Sysmiss | 26 |