Cluster size development as a function of cluster age for exposed clusters. The observational values were taken from Wolff et al. (2007), and simulation data points are from Goodwin & Bastian (2006). A linear fit in the log-log space is shown as drawn line, scaled versions of the results of Goodwin & Bastian (2006) for instantaneous gas expulsion with 10% (short dashed line), 30% (long dashed line), and 50% (dotted line) star formation (SF) efficiency are shown.