| Value | Category |
|---|---|
| 1 | Only 1 week |
| 2 | More than 1 week to 2 weeks |
| 3 | More than 2 weeks to 1 month |
| 4 | More than 1 month to 2 months |
| 5 | More than 2 months to 3 months |
| 6 | More than 3 months to 6 months |
| 7 | More than 6 months to 12 months |
| 8 | More than 12 months |
| Sysmiss |