| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 1 |
6.7%
|
|
| 2000 | 2 |
13.3%
|
|
| 2001 | 6 |
40%
|
|
| 2003 | 4 |
26.7%
|
|
| 2004 | 2 |
13.3%
|