Stacked histograms of the observed red-shifted maximum velocities compared to the free-fall velocities (top), and blue-shifted maximum velocities compared to the escape velocity (bottom), where the total value in each bin is the number of sources in both Lupus and Upper Scorpius. The dashed black line in each panel shows the Gaussian distributions fitted to the histogram data, with the centroid (µ) and standard deviation (σ) of this fit noted in the top left corner.