| Value | Category | Cases | |
|---|---|---|---|
| 2001 | 5 |
5.3%
|
|
| 2002 | 10 |
10.6%
|
|
| 2003 | 16 |
17%
|
|
| 2004 | 25 |
26.6%
|
|
| 2005 | 29 |
30.9%
|
|
| 9999 | 9999. Don't know | 9 |
9.6%
|
| Sysmiss | 905 |