Radio luminosity density L_1.4 [W Hz⁻¹] and redshift for RxAGN (black points). Red points correspond to the selected redshift and radio luminosity sample of RxAGN used in this work and are contained within log L_1.4 [W Hz⁻¹] ∈ [24, 26] and z ∈ [0, 4]. The histograms show the distribution of radio luminosity and redshift for all RxAGN and the RxAGN sample used in this work with black and red bars, respectively. The radio luminosity-redshift distribution is used to choose a complete sample of RxAGN.