cover-up vs fraud

cover-up

noun
  • An attempt to conceal or disguise something, especially a wrongdoing or a mistake. 

  • An item of clothing to be worn over a swimsuit while not in the water. 

fraud

noun
  • Any act of deception carried out for the purpose of unfair, undeserved and/or unlawful gain. 

  • The assumption of a false identity to such deceptive end. 

  • A person who performs any such trick. 

  • The crime of stealing or otherwise illegally obtaining money by use of deception tactics. 

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