| Value | Category | Cases | |
|---|---|---|---|
| 2002 | 8 |
13.3%
|
|
| 2003 | 33 |
55%
|
|
| 2004 | 12 |
20%
|
|
| 2005 | 7 |
11.7%
|
|
| Sysmiss | 235 |