hush up vs persuade

hush up

verb
  • To keep secret, to prevent from becoming known. 

  • To become quiet; to cease making sounds. 

persuade

verb
  • To successfully convince (someone) to agree to, accept, or do something, usually through reasoning and verbal influence. 

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