| Value | Category | Cases | |
|---|---|---|---|
| -2 | Refusal to answer | 0 |
0%
|
| -1 | Don't know | 0 |
0%
|
| 1996 | 1 |
10%
|
|
| 1997 | 1 |
10%
|
|
| 1999 | 2 |
20%
|
|
| 2000 | 5 |
50%
|
|
| 2001 | 1 |
10%
|
|
| Sysmiss | 1555 |