unselfishness vs usury

unselfishness

noun
  • The state of being unselfish. 

usury

noun
  • An exorbitant rate of interest, in excess of any legal rates or at least immorally. 

  • The practice of lending money at such rates. 

  • The practice of lending money at interest. 

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