| 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 |