| Value | Category | Cases | |
|---|---|---|---|
| 2002 | 5 |
15.2%
|
|
| 2003 | 4 |
12.1%
|
|
| 2004 | 9 |
27.3%
|
|
| 2005 | 13 |
39.4%
|
|
| 9999 | 9999. Don't know | 2 |
6.1%
|
| Sysmiss | 966 |