confidence vs unconfidence

confidence

noun
  • A feeling of certainty; firm trust or belief; faith. 

  • Information held in secret; a piece of information shared but to thence be kept in secret. 

  • Self-assurance. 

unconfidence

noun
  • Absence of confidence; uncertainty; doubt. 

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