aplomb vs coolheadedness

aplomb

noun
  • Self-confidence; poise; composure. 

  • The apparent elegance and precision exhibited by a confident, accomplished dancer. 

  • The perpendicular; perpendicularity. 

coolheadedness

noun
  • The state or characteristic of being coolheaded. 

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