presumption vs unconfidence

presumption

noun
  • the condition upon which something is presumed 

  • the belief of something based upon reasonable evidence, or upon something known to be true 

  • the act of presuming, or something presumed 

  • An inference that a trier of fact is either permitted or required to draw under certain factual circumstances (as prescribed by statute or case law) unless the party against whom the inference is drawn is able to rebut it with admissible, competent evidence. 

unconfidence

noun
  • Absence of confidence; uncertainty; doubt. 

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