keep under wraps vs uncover

keep under wraps

uncover

verb
  • To remove one's hat or cap as a mark of respect. 

  • To reveal the identity of. 

  • To expose the genitalia. 

  • To remove a cover from. 

  • To show openly; to disclose; to reveal. 

  • To expose (lines of formation of troops) successively by the wheeling to right or left of the lines in front. 

How often have the words keep under wraps and uncover occurred in a corpus of books? (source: Google Ngram Viewer )