De-projected semi-major axis of inner and outer rings, in physical units (upper panel) and normalised to R_25.5 (middle panel), and intrinsic ellipticity (lower panel) as a function of the revised numerical Hubble stage. In the x-axis we have added small random offsets (≲0.3) to the T values (integers) for the sake of avoiding point overlapping. The colour palette and symbol style separate inner and outer rings. The lines indicate the running mean. For each bin, the error bars indicate the standard deviation of the mean.