disuse vs thoughtlessness

disuse

noun
  • The state of not being used; neglect. 

verb
  • To cease the use of. 

thoughtlessness

noun
  • heedless disregard for the consequences of one's actions 

  • disregard for other's feelings 

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