exculpation vs liberation

exculpation

noun
  • That which exculpates; an excuse. 

  • The act of exculpating from alleged fault or crime. 

liberation

noun
  • The act of liberating or the state of being liberated. 

  • The achievement of equal rights and status. 

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