| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 1 |
0.9%
|
|
| 1998 | 2 |
1.8%
|
|
| 1999 | 43 |
39.1%
|
|
| 2000 | 42 |
38.2%
|
|
| 2001 | 22 |
20%
|
|
| Sysmiss | 11348 |