diffidence vs extroversion

diffidence

noun
  • The state of being diffident, timid or shy; reticence or self-effacement. 

extroversion

noun
  • A personality orientation towards others and things outside oneself; behavior expressing such orientation. 

  • The condition of being inside out, especially in relation to the bladder. 

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