anxiety vs confidence

anxiety

noun
  • An uneasy or distressing desire (for something). 

  • An unpleasant state of mental uneasiness, nervousness, apprehension and obsession or concern about some uncertain event. 

  • A state of restlessness and agitation, often accompanied by a distressing sense of oppression or tightness in the stomach. 

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. 

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