Two stellar populations, young and evolved, shown as blue circles and red diamonds, respectively. The vertical lines indicate the 68% confidence intervals from the fit. When polarisation data are available, we report the fit with lowest and highest contribution from scattered AGN light as the downward and upward empty triangles respectively. For clarity, we do not add the 68% confidence intervals for the polarisation-subtracted fits. Left: masses of the two stellar populations versus redshift. Right: ages of the two stellar populations where the black line shows the oldest universe age as a function of redshift assuming the standard cosmological concordance model (Sect. 1). The dashed line represents the age of a galaxy for z_form = 10. We note that the 68% confidence interval can be smaller than point size and polarisation-subtracted fits are mainly contained in the 68% confidence intervals when scattered AGN light is ignored.