Distribution of L₁₄₄ of quasars with z <  3.0 as a function of L₂₅₀. The solid black line shows the FIRC relation given by Gürkan et al. (2018). Circles indicate sources detected in both bands: left-pointing arrows and black down-pointing arrows represent limits in 250 μm and 144 MHz bands. Points (except LOFAR limits) are colour coded by their ℛ values. We expect to get a flatter slope with increasing redshift due to the evolution of FIRC (Calistro Rivera et al. 2017), which is indicated by a black arrow.