fuck about vs jerk off

fuck about

verb
  • To fool around. 

  • To waste time with unimportant activities, often used as an admonition to urge the other party to stop wasting time. 

jerk off

verb
  • To deceive. 

  • To masturbate, usually a male. 

  • To do nothing; to waste time. 

noun
  • An act of masturbation. 

  • A stunt in which the performer is suddenly pulled off a horse, etc. by means of a cable. 

  • An annoying person. 

How often have the words fuck about and jerk off occurred in a corpus of books? (source: Google Ngram Viewer )