the madman

In the classic book, The professor and the madman: A Tale of Murder, Insanity, and the Making of The Oxford English Dictionary , Simon Winchester tells one of the first stories of truly successful mass collaboration.  In the story, Winchester describes how one man, who it turned out was quite mad, contributed a disproportionately large quantity of the definitions used to create it.  

I've seen this pattern repeated many times in my studies, though the figures on the leading edge of the charts generally don't tend to be crazy.  Its fascinating how consistent the pattern describing the volume of contributions produced by individuals in open settings is, a few people always end up doing most of the work.  I was wondering, does anyone have any data about the actual fraction of definitions produced by different individuals for the original OED?  It would make an awesome figure for any text about volunteer based mass collaboration (such as the dissertation I should be writing right now).