confidence vs uncertainty

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. 

uncertainty

noun
  • Doubt; the condition of being uncertain or without conviction. 

  • A parameter that measures the dispersion of a range of measured values. 

  • Something uncertain or ambiguous. 

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