Anybody and anyone

After reading a sentence written by a student, I needed to refresh my memory regarding the indefinite pronouns anybody and anyone.
First, I reached for a frequently used book in my bookshelf: the Longman Grammar of Spoken and Written English by Biber et al. The conclusion I made, based on information found on pages 351-353, was that the two indefinite pronouns mentioned above differ the most in terms of usage frequency. In English: anybody is used more frequently in AmE than BrE and it is considered to be more informal than anyone.

This finding was corroborated via Cambridge Dictionaries Online:
http://dictionary.cambridge.org/grammar/british-grammar/anyone-anybody-or-anything