Are you implying that most AGI's (assume these intelligences can go FOOM) would not result in human extinction?
Questions about fractions of infinite sets require an enumeration strategy to be specified - or they don't make much sense. Assuming lexicographic ordering of their source code - and only considering the set of superintelligent programs - no: I don't mean to imply that.
From Geoff Anders of Leverage Research:
Not a surprising result, perhaps, but the details of how Geoff taught AGI danger and the reactions of his students are quite interesting.