| Value | Category |
|---|---|
| 1 | More than two hours each day (10+ hours/week) |
| 2 | About one hour each day (~5 hrs/ week) |
| 3 | About a half hour each day (~3hrs/week) |
| 4 | A few minutes each day (<1 hr/week) |
| 5 | None (0) |
| 6 | Don't know |
| 7 | Refused to answer |
| 8 | Outlier set to missing |
| 9 | Inconsistency set to missing |
| 10 | Not applicable |