Scholarly productivity in the discipline of history

    How many books on average do historians publish throughout their academic careers?  What is the norm?  Certianly studies of the kind exist, so I tried doing google key-wording on the issue.  Since nothing relevant immediately came up, I decided to do a simple and very rough survey.  I looked at various curriculum vita at random that were available on the Internet, and calculated average figures.  (It was by no mean a 'scientific analysis').  I selected for roughly 1977 Ph.D. graduation date, with universities ranging from the University of Detroit to Stanford.  The average result was approximately 6 books.  Prominent historians, whose publication data far exceed this, such as Louis A. Perez Jr, Stuart B. Shwartz, and Ernest R. May, were NOT included in the survey, which would most likely have skewed the findings drastically upward.  Again, this is not a 'serious' study--but the findings are suggestive.