I know that MSAR has past years data for several areas, but I'm interested in looking at trends in things like median MCAT, GPA, # of applicants/interviews/matriculates for IS/OOS. Any one know if this data is accessible somehow?
No. The MSAR is a now a yearly updated subscription and previous data is not available. The AAMC reports that are free do not have the granularity you are looking for