PDF of gas fraction for old clusters (z_f > 1, with blue steps) and young clusters (z_f < 0.5, as pink shaded area). The top panel shows the gas-fraction within R_500c and the bottom panel shows the gas-fraction within R_500c corrected with the amount of gas that was inside the halo at formation time and have been ejected outside outside the virial radius (f_ej). In both cases we consider haloes in the range of mass M_200c ∈ [1 − 2]×10¹⁴ M_⊙. We see that the amount of ejected gas accounts for much of the difference in f_g between old and young clusters.