| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -8 | Refusal (spontaneous) | 0 |
0%
|
| -7 | Does not apply | 0 |
0%
|
| 1 | One year or less | 1 |
25%
|
| 4 | 1 |
25%
|
|
| 15 | 1 |
25%
|
|
| 16 | 1 |
25%
|
|
| Sysmiss | 348 |