Evolution of r₀ with d for clusters of different masses in different redshift slices. The points plotted are for the fixed slope γ = 2.0. The green dashed line shows the fit when γ = 2.0 and the red dashed line shows the overall fit obtained for the data points considering a free slope. The analytic approximation in the ΛCDM case obtained by Younger et al. (2005) is shown by the dashed black line. The different redshift slices are colour coded as mentioned in the figure.