avowal vs revelation

avowal

noun
  • An open declaration of affirmation or admission of knowledge. 

revelation

noun
  • The act of revealing or disclosing. 

  • Something that turns out to be a great success. 

  • Something dramatically disclosed. 

  • A manifestation of divine truth. 

  • Something that is revealed. 

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