low-pressure vs unconcerned

low-pressure

adj
  • The opposite of high-pressure, defined by contrast. 

unconcerned

adj
  • Indifferent and having no interest; aloof. 

  • Not anxious, apprehensive, or worried. 

  • Having no involvement. 

How often have the words low-pressure and unconcerned occurred in a corpus of books? (source: Google Ngram Viewer )