| Value | Category | Cases | |
|---|---|---|---|
| -2 | Refusal to answer | 0 |
0%
|
| -1 | Don't know | 0 |
0%
|
| 0 | 1 |
16.7%
|
|
| 1998 | 1 |
16.7%
|
|
| 2000 | 2 |
33.3%
|
|
| 2001 | 2 |
33.3%
|
|
| Sysmiss | 2627 |