| Value | Category | Cases | |
|---|---|---|---|
| 2003 | 10 |
25%
|
|
| 2004 | 5 |
12.5%
|
|
| 2005 | 19 |
47.5%
|
|
| 2006 | 6 |
15%
|
|
| 9998 | DK | 0 |
0%
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 152 |