Irish bull vs hoax

Irish bull

noun
  • A ludicrous, incongruent or logically absurd statement. 

hoax

noun
  • Anything deliberately intended to deceive or trick. 

verb
  • To deceive (someone) by making them believe something that has been maliciously or mischievously fabricated. 

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