| Value | Category | Cases | |
|---|---|---|---|
| 2002 | 2 |
3.9%
|
|
| 2003 | 6 |
11.8%
|
|
| 2004 | 13 |
25.5%
|
|
| 2005 | 29 |
56.9%
|
|
| 9999 | 9999. Don't know | 1 |
2%
|
| Sysmiss | 948 |