heedlessness vs laxity

heedlessness

noun
  • The state or character of being heedless 

laxity

noun
  • Moral looseness; lack of rigorousness or strictness. 

  • The state of being lax; looseness, lack of tension. 

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