self-confidence vs simplicity

self-confidence

noun
  • A measure of one's belief in one's own abilities 

  • The state of being self-confident 

simplicity

noun
  • Lack of subtlety or abstruseness; clarity 

  • Lack of artificial ornament, pretentious style, or luxury; plainness 

  • Lack of complication; efficiency. 

  • The quality or state of being not complex, or of consisting of few parts 

  • The quality or state of being unmixed or uncompounded 

  • Lack of sharpness of mind; lack of ability to think using complex ideas; stupidity 

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