| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 1 |
1.3%
|
|
| 1991 | 1 |
1.3%
|
|
| 1992 | 14 |
17.7%
|
|
| 1993 | 20 |
25.3%
|
|
| 1994 | 12 |
15.2%
|
|
| 7777 | 31 |
39.2%
|
|
| Sysmiss | 9550 |