Upper left: distribution of the abundance of the iron plateau component Z_plateau. The dashed line indicates the weighted average value ⟨Z_plateau⟩ = 0.38 Z_⊙. The dashed curve shows a normalized Gaussian with σ = 0.11 Z_⊙, corresponding to the average statistical error, and μ = 0.38 Z_⊙, corresponding to the weighted average value. Upper right: abundance of the iron plateau plotted against cluster redshift. The black curve and shaded area show the best-fit function Z_plateau = Z_plateau, 0 ⋅ (1 + z)^{−γ_plateau} with Z_plateau, 0 = (0.41 ± 0.02) Z_⊙ and γ_plateau = 0.21 ± 0.18, which are obtained by fitting the weighted average values and uncertainties of the four bins shown as blue solid lines and shaded areas. Lower left: distribution of the normalization of the iron peak component Z_peak. The dashed line indicates the weighted average value ⟨Z_peak⟩ = 0.52 Z_⊙. The dashed curve shows a normalized Gaussian with σ = 0.42 Z_⊙, corresponding to the average statistical error, and μ = 0.52 Z_⊙, corresponding to the weighted average value. Lower right: normalization of the iron peak component Z_peak plotted against cluster redshift. The black curve and shaded area show the best-fit function Z_peak = Z_peak, 0 ⋅ (1 + z)^−γ_peak with Z_peak, 0 = (0.68 ± 0.07) Z_⊙ and γ_peak = 0.79 ± 0.53.