tough break vs unluck

tough break

noun
  • A situation resulting in misfortune or hardship; an instance of bad luck. 

intj
  • An interjection of mild or insincere sympathy for someone else's misfortune. 

unluck

noun
  • Absence or lack of luck; lucklessness; bad luck; misfortune. 

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