college rebounding rules?

[schugeorge67]

I was looking at rebounding records and stats of certain players and I keep seeing the stats seperated before 1973 and after 73. why is this? was there a rule change pertaining to rebounding? What significance does '73 have? P.S. the stats were of colegiate players. Here's a link to the records: (which I find informative and interesting)

http://www.ncaa.org/wps/portal/ncaahome ... 009ff.html

After you go to the site, click on "the tournament" to view the PDF file and scroll down to rebounding records and you'll notice they are seperated pre and post 1973.

[Dive4Five]

I am assuming it is because Freshman became eligible to play in 1973. Don't know if that is the right answer or not