help oneself vs take it

help oneself

verb
  • Used other than figuratively or idiomatically: see help. 

  • To serve oneself, especially to take food or other supplies, rather than wait to be served by another; used to indicate friendly permission or invitation. 

  • To exhibit self-control. 

  • To take something freely; to serve oneself without restraint. 

take it

verb
  • Used other than figuratively or idiomatically: see take, it. 

  • to suppose 

  • to reluctantly accept or believe; to acquiesce 

  • to start doing 

How often have the words help oneself and take it occurred in a corpus of books? (source: Google Ngram Viewer )