RLF ratio evolution. Left: ratio evolution over different redshift bins. Right: separated FRI (above) and FRII (below) space density evolution plots corresponding to the ratio evolution plot in the left panel. In both figures, we added the Gendre et al. (2013) data points for the higher end of the luminosity range, such that we can further constrain the local RLF, which was fitted with a broken power law from Eq. (8) and corresponding values from Table 1, where we used a 1σ confidence interval. We removed radio luminosity bins which only contain a single source. The 1σ bars from our RLFs are including z_max errors, Poisson errors, completeness corrections errors, and classification errors, as explained in Sects. 4.1.2 and 4.2.