| 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 |