Posterior distributions of the total matter density parameter Ω_M. The blue, orange, and green histograms show the results for the low, intermediate, and high redshift cluster samples, respectively. The red-filled histogram exhibits the posterior distribution combining all redshifts together; the dashed red line indicates the median of the distribution. The black curve displays the posterior distribution obtained from the analysis of the CMB data by Planck Collaboration VI (2020).