| Value | Category | Cases | |
|---|---|---|---|
| 99 | Don't Know | 0 |
0%
|
| 1997 | 1 |
1%
|
|
| 1999 | 2 |
2%
|
|
| 2000 | 14 |
14%
|
|
| 2001 | 26 |
26%
|
|
| 2002 | 24 |
24%
|
|
| 2003 | 24 |
24%
|
|
| 2004 | 9 |
9%
|
|
| Sysmiss | 1456 |