The data shown in this table for 2021Q1 and 2021Q2 has been imputed based on data covering the period 2019Q4 - 2020Q4 and 2021Q3 - 2021Q4. This imputation was undertaken because respondents in 2021Q1 and 2021Q2 only were asked whether they had worked overtime during the reference week, but not whether this overtime was paid or unpaid.