Cumulative evolution of the fraction of catastrophic outliers ϵ (in percentage points) as a function of the number of time-delay estimations. To produce the plot, the curves are first sorted according to the depth of their absolute minimum μ, indicated in the colour bar. Each black line (solid, dashed and dotted) represents a different subsample (see text for details). The coloured diamonds show the value of ϵ for the D3CS combined samples; the corresponding number of estimations are indicated in parenthesis.