diligence vs hard work

diligence

noun
  • The process by which persons, lands, or effects are seized for debt; process for enforcing the attendance of witnesses or the production of writings. 

  • A public stage-coach. 

  • Steady application; industry; careful work involving long-term effort. 

  • The qualities of a hard worker, including conscientiousness, determination, and perseverance. 

  • Carefulness. 

hard work

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