| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | Less than one month | 1 |
5.6%
|
| 5 | 1 |
5.6%
|
|
| 6 | 1 |
5.6%
|
|
| 12 | One year or more | 15 |
83.3%
|
| Sysmiss | 536 |