heed vs obey

heed

verb
  • To mind; to regard with care; to take notice of; to attend to; to observe. 

noun
  • Careful attention. 

obey

verb
  • To do as one is told. 

  • To do as ordered by (a person, institution etc), to act according to the bidding of. 

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