| Value | Category | Cases | |
|---|---|---|---|
| -2 | Refusal to answer | 0 |
0%
|
| -1 | Don't know | 1 |
1.6%
|
| 1990 | 1 |
1.6%
|
|
| 1992 | 1 |
1.6%
|
|
| 1995 | 2 |
3.2%
|
|
| 1996 | 1 |
1.6%
|
|
| 1997 | 1 |
1.6%
|
|
| 1999 | 2 |
3.2%
|
|
| 2000 | 7 |
11.3%
|
|
| 2001 | 46 |
74.2%
|
|
| Sysmiss | 7787 |