brush up on vs go over

brush up on

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 brush up on and go over occurred in a corpus of books? (source: Google Ngram Viewer )