heedless vs reckless

heedless

adj
  • Unaware; without noticing; careless; inattentive. 

reckless

adj
  • Indifferent or oblivious to danger or the consequences thereof. 

  • Careless or heedless; headstrong or rash. 

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