| Value | Category | Cases | |
|---|---|---|---|
| 1991 | 1 |
0.5%
|
|
| 1998 | 4 |
2%
|
|
| 1999 | 69 |
34%
|
|
| 2000 | 71 |
35%
|
|
| 2001 | 58 |
28.6%
|
|
| Sysmiss | 11255 |