| Value | Category | Cases | |
|---|---|---|---|
| -2 | Refusal to answer | 1 |
5.6%
|
| -1 | Don't know | 0 |
0%
|
| 0 | 1 |
5.6%
|
|
| 1991 | 1 |
5.6%
|
|
| 1997 | 1 |
5.6%
|
|
| 2000 | 6 |
33.3%
|
|
| 2001 | 8 |
44.4%
|
|
| Sysmiss | 2615 |