Occurrence rates for the different planet categories as a function of [Fe/H] (top row) and [Mg/Fe] (bottom row). The occurrence rates of giant planets increase as expected with [Fe/H], so most of the α-rich stars and almost all of the halo stars form no giant planets due to the overall lower metallicities of those populations. Water-rich planets are common (~50%) around both α-poor and α-rich stars with [Fe/H] > −0.5. There is no strong relation in the fraction of giant planets or super-Earths with [Mg/Fe], although [Mg/Fe]-poor stars are more likely to form more giant planets and super-Earths since they are typically [Fe/H]-rich.