follow up vs go over

follow up

verb
  • To take further actions remaining after an event; to continue, revisit, or persist; especially, to maintain communication or verify. 

go over

verb
  • To create a response or impression. 

  • Used other than figuratively or idiomatically: see go, over. 

  • To look at carefully; to scrutinize; to analyze. 

  • To score a try. 

How often have the words follow up and go over occurred in a corpus of books? (source: Google Ngram Viewer )