| Value | Category | Cases | |
|---|---|---|---|
| 2001 | 9 |
1.9%
|
|
| 2002 | 32 |
6.9%
|
|
| 2003 | 44 |
9.5%
|
|
| 2004 | 48 |
10.3%
|
|
| 2005 | 66 |
14.2%
|
|
| 2006 | 184 |
39.6%
|
|
| 2007 | 53 |
11.4%
|
|
| 8888 | don't know | 29 |
6.2%
|
| Sysmiss | 1 |