Velocities in the Galactocentric cylindrical coordinate frame as a function of [Fe/H]. Left panels: all sample stars are shown (grey dots). The mean value per [Fe/H] bin is shown for the thin- (orange), hαmr- (purple), and hαmp thick-disc (blue) populations. The mean value has been computed between the 5% and 95% quantiles of the sample to avoid extreme values. The ±1σ error bars are shown. The dashed lines are the linear fits. Right panels: BGM predictions (orange, purple and blue solid lines) for the APOKASC sample as a function of [Fe/H] compared to the linear fits done using observations (dashed lines). The ±1σ error bars are shown with the shadow zones.