heedful vs unconcerned

heedful

adj
  • Paying close attention; mindful. 

  • Taking heed. 

unconcerned

adj
  • Not anxious, apprehensive, or worried. 

  • Having no involvement. 

  • Indifferent and having no interest; aloof. 

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