intelligibility vs mumbo jumbo

intelligibility

noun
  • The quality of recorded speech of every word being understandable. 

  • That which is intelligible; the degree to which something is intelligible. 

mumbo jumbo

noun
  • Any object of superstition; religious words and/or actions which are seen as superstitious or fraudulent. 

  • A deity or other supernatural being said to have been worshipped by certain West African peoples; an idol. 

  • Any confusing or meaningless speech; nonsense, gibberish. 

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