Age vs. radius for each superbubble. The blue crosses with vertical lines show the average ages of the stellar associations powering the superbubbles for the 16 pc stellar associations (HST ages) and their uncertainties. The dot-dashed blue line is a linear fit to the blue crosses. The red crosses with vertical lines show the dynamical derived CO ages of the superbubbles and their uncertainties, assuming they follow a self-similar solution driven by SNe (η = 1/4), which is the closest physical model that matches the HST ages (see Fig. 10). The dashed red line is a linear fit to the red crosses. The solid grey line shows a linear fit to the CO-derived values if we used a self-similar solution describing continual radiative energy injection models (η = 1/2).