Median radial migration rate of stars. As in Figure 6, each color corresponds to a population of stars, followed at different epochs (different panels). The quantity plotted is the median of the difference between the radius at the given epoch (the quantity on the x-axis) and the birth radius, divided by the time difference between the two epochs, with the convention of a positive value for an outward migration. By considering the instantaneous radius (instead of the average), the migration measured here includes both the blurring and churning effects.