cool as a cucumber vs unconcerned

cool as a cucumber

adj
  • Calm and composed even in difficult or frustrating situations; self-possessed. 

unconcerned

adj
  • Not anxious, apprehensive, or worried. 

  • Having no involvement. 

  • Indifferent and having no interest; aloof. 

How often have the words cool as a cucumber and unconcerned occurred in a corpus of books? (source: Google Ngram Viewer )