| Value | Category | 
|---|---|
| 1 | Past 7 days | 
| 2 | Btween 14 to 7 days ago | 
| 3 | May 2020 | 
| 4 | April 2020 | 
| 5 | March 2020 | 
| 6 | Feb 2020 | 
| 7 | Jan 2020 | 
| 8 | Before Jan 2020 | 
| 9 | 9 | 
| 10 | 10 | 
| 11 | 11 | 
| 12 | 12 | 
| 13 | 13 | 
| 14 | 14 | 
| 15 | 15 | 
| 16 | 16 | 
| 17 | Don't know | 
| 18 | Refused to answer | 
| 19 | Outlier set to missing | 
| 20 | Inconsistency set to missing | 
| 21 | Not applicable |