| Value | Category | Cases | |
|---|---|---|---|
| 2001 | 3 |
3.6%
|
|
| 2002 | 7 |
8.4%
|
|
| 2003 | 11 |
13.3%
|
|
| 2004 | 29 |
34.9%
|
|
| 2005 | 27 |
32.5%
|
|
| 2006 | 6 |
7.2%
|
|
| Sysmiss | 8051 |