.."nothing to back them up..."
Sorry, check the Fraternitiy Executives Association. I included a link below to their website, but your national office will have copies of all their reports and surveys - that's where all these comparisons come from. The FEA has taken detailed surveys of its member fraternities for decades. I used to be on our national staff and I'm familiar with the reports - at least from the time I was there.
The NIC isn't much help, plus some of the most prominent national fraternities are no longer members. It's ironic that the president of the FEA is a Phi Delt yet Phi Delt is no longer a member of NIC. The CFEA is a very collegial organization and very cooperative.
http://www.fea-inc.org/index.shtml