Time evolution of the metric (k₂ + k₄)/(k₁ + k₃), where k_i correspond to the numbers of synthetic objects in quadrants i (i = 1,2,3,4) that are defined by the center of the family and value β = 0°, for synthetic Flora, Koronis, and Eos families (red lines). The spread corresponds to 100 different selections of objects (we simulate 10 times more objects to reach a better statistics). the upper curve denotes the 90% quantile and the bottom 10%. Thick horizontal line is the observed ratio (k₂ + k₄)/(k₁ + k₃) with the uncertainty interval.