| Variable | Year | Supplement |
|---|---|---|
| IMPINCFLG | 2022 | In both sample adult and child questionnaires |
| IMPINCFLG | 2021 | In both sample adult and child questionnaires |
| IMPINCFLG | 2020 | In both sample adult and child questionnaires |
| IMPINCFLG | 2019 | In both sample adult and child questionnaires |