| Value | Category | Cases | |
|---|---|---|---|
| 1984 | 1 |
10%
|
|
| 1997 | 1 |
10%
|
|
| 1998 | 2 |
20%
|
|
| 2001 | 3 |
30%
|
|
| 2002 | 3 |
30%
|
|
| Sysmiss | 1838 |