bum rap vs exculpation

bum rap

noun
  • An undeservedly unfavorable portrayal or reputation. 

  • A false accusation, or an injustice, especially one that leads to imprisonment. 

exculpation

noun
  • The act of exculpating from alleged fault or crime. 

  • That which exculpates; an excuse. 

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