unluck vs wretchedness

unluck

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

wretchedness

noun
  • A state of prolonged misfortune, privation, or anguish. 

  • An unhappy state of mental or physical suffering. 

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