Based on the data presented in Figure , I can suggest several conclusions about the evolution of young stars. The results of the Kolmogorov--Smirnov (KS) tests with the data presented here and those of Choi & Herbst (1996) on similar regions of the histogram indicate that there is something which holds stars near eight day periods. Stars in different regions also seem to share a similar mechanism which regulates the fast rotators. Further, it seems that stars migrate from the slow rotating (SR) group to the fast rotating (FR) group as a function of time. To gain the most information out of the data presented here one can combine these data with those of other authors. Before that can be done, one should first discuss the biases in the data sets.