Left: Probability density for the source redshift. Right: Merger rate density as a function of redshift. In both panels, the coloured regions refer to the two components of the EVOLVING model, whereas the areas delimited by the dashed black line refers to the common evolution of the POWERLAW+PEAK model. The hatched areas mark the extrapolation beyond detector horizon for the corresponding mass range. (a) PDF. (b) Merger rate density.