Have you checked out LawSchoolTransparency.com?
This site is aiming to make law school employment statistics as transparent as possible; its mission, according to the website, includes the following:
[T]o become a clearinghouse for employment data from ABA-approved law schools. Additionally, we provide a closer look at how career services and admissions offices work together at ABA-approved law schools to develop relationships with employers and assist students in finding work. We believe that publishing employment lists will supplement, rather than replace, the many job placement summaries already provided by schools, publications, and legal scholars.
Data is just being collected now, so do keep an eye on that space. It could provide some very interesting information.

Comments
This is a wonderful initiative to take on. I wonder if any, or many, law schools will be reluctant to share data.
It will certainly be interesting to see the cooperation levels!