Tzippi: Sounds like common sense to me.
Cherrybim:
Finally, the school alumni data, is NOT what the age gap concept it based on. It was based on various studies one of which was a study of class sizes that showed younger grades being larger than the older grades. Perhaps you will argue that schools don’t have accurate date on the number of students in their classes. The alumni data is being put together simply as a way of showing the community how serious it is NOT for proving the concept.