| Value | Category | 
|---|---|
| 1 | In the past 7 days | 
| 2 | In the 7 days before that (between 14 to 7 days ago) | 
| 3 | May 2020 | 
| 4 | April 2020 | 
| 5 | March 2020 | 
| 6 | February 2020 | 
| 7 | January 2020 | 
| 8 | Before January 2020 | 
| 9 | June 2020 | 
| 10 | July 2020 | 
| 11 | August 2020 | 
| 12 | Don't know | 
| 13 | Refused to answer | 
| 14 | Outlier set to missing | 
| 15 | Inconsistency set to missing | 
| 16 | Not applicable |