arduousness vs hardship

arduousness

noun
  • The state of being arduous. 

hardship

noun
  • Difficulty or trouble; hard times. 

  • A burden, a source of difficulty that could impose a barrier. 

verb
  • To treat (a person) badly; to subject to hardships. 

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