Star-formation rates in the sample of 12 post-starburst galaxies. MACS1149-JD1 is highlighted in red in all panels as this galaxy is at substantially higher redshift (z = 9.11) than the others in the sample. Upper panel: observed quiescent star-formation rate ℛ_SF plotted against the length of quiescence period. This period is measured up to the point of observation, so t_qui effectively indicates the time elapsed since the end of starburst activity. This shows a strong positive correlation, with a Pearson coefficient (weighted by the error bounds) of 0.93. Middle panel: as above, except the y-axis is star-formation rate surface density (). This removes the correlation seen in the upper panel, with a Pearson coefficient of −0.02 (when removing the clear outlier A1689-zD1, as labelled). Lower panel: y-axis as specific star-formation rate, which is adjusted for galaxy mass where SSFR = ℛ_SF/M_*. If removing the labelled outlier A1689-zD1, this now gives a non-negligible negative correlation of weighted Pearson coefficient −0.64.