divulge vs open up

divulge

verb
  • To make public or known; to communicate to the public; to tell (information, especially a secret) so that it may become generally known. 

  • To indicate publicly; to proclaim. 

open up

verb
  • To reveal oneself; to share personal information about oneself; to become communicative. 

  • Synonym of cheat out (“to face or turn toward the audience more than would be natural”) 

  • To begin running, driving, travelling, etc., at maximum speed. 

  • To commence firing weapons. 

  • To rain. 

  • To open. 

  • To widen. 

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