cover-up vs dissimulation

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. 

dissimulation

noun
  • The act of concealing the truth; hypocrisy or deception. 

  • Hiding one's feelings or intentions. 

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