Hmm...interesting. I'm not sure how the data reflects things like a core curriculum (where I read a lot of these) which is a general requirement...or maybe looks at the classes themselves which may be in one department or another. This could be further confused with common requirements being taught by professors in different fields, and so their syllabi might be classified differently? Curious.
Edit: the best way to investigate would be if it is all weighted by number of students or something, though that might be tough to do.
TBH, though, I can't really make any sense of this data. The overall result says that Leviathan appears just over 200 times overall at Ivies (i.e. fewer times than in Ivy poli sci syllabi). And for most assigned business books, "Asking the Right Questions" appears 450 times, which should put it at the top overall, but it doesn't appear in the top 10.