self-confidence vs self-possession

self-confidence

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

  • The state of being self-confident 

self-possession

noun
  • confidence in one's own powers 

  • calmness and composure, especially when under stress 

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