Median absolute deviations (MAD) observed for  ⟨ Δν ⟩  (top) and ν_max (bottom) for the different methods as a function of the timespan of the dataset. Colour coding the same as in Fig. 3 with red for OCT, green for COR:EACF, black for COR:UP and blue for CAN. The 400 day results of COR:UP agree with the 600 day results and hence the MAD is 0.000 and not shown. The dashed lines indicate linear fits through the data (with same colour-coding) in log-scale. See text for further details.