29. Cornell 0.049% (would rank 16th (0.16%) if CAS only)
30. UCLA 0.036%
31. Utah 0.035%
32. Penn 0.034% (would rank 27th (0.06%) if CAS only)
The ranking is based on the % of students who go to Yale Law School, which is by a very wide margin, the nation's top-ranked law school (ranked #1 every year since the US News rankings were first published in 1987, and the only law school to ever be ranked #1 - other schools fluctuate between being ranked #2-4).
The yield rate of Yale Law is about 85% (by comparison, Harvard Law's yield rate is only 60%), meaning almost any law school applicant who gets into Yale chooses to go there, making this a great way to rank the quality of undergraduate prelaw programs - aside from the obvious fact that Yale is the best, that is.
Formula = Makeup of Yale Law School, New Haven, Connecticut enrollment / Number of undergrads (from wikipedia).