hardship vs worsen

hardship

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

noun
  • Difficulty or trouble; hard times. 

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

worsen

verb
  • To make worse; to impair. 

  • To become worse; to get worse. 

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