q_TIR versus redshift for star-forming galaxies and associated power-law fits derived using: all data points (magenta points and solid line; 1σ uncertainty region shaded), excluding the lowest redshift bin (black dashed line), including the local value of Bell (2003); i.e. fitting to all the magenta points as well as the green point; green dotted line with 1σ uncertainty region shaded, and anchoring to the local value of Bell (2003) by fitting to the function 2.64(1 + z)^x where x is the free parameter (blue dot-dashed line). Also shown is the median in each redshift bin calculated using only directly-measured values (i.e. without applying a survival analysis; cyan squares), and the associated fit (solid cyan line).