Has anyone compiled all the NTSB accident reports and broke down the percentages for cause of accident and fatalities?
There's a book called "The Killing Zone - How and Why Pilots Die" by Paul A. Craig which has a great deal of statistical work in it around aircraft accidents which may be useful to you. It's an alarming title which might make you think it's some sort of sky is falling mentality, but it's actually very sensible, statistics-based information about aviation accidents.