clemency vs pardoning

clemency

noun
  • A pardon, commutation, or similar reduction, removal, or postponement of legal penalties by an executive officer of a state. 

  • The gentle or kind exercise of power; leniency, mercy; compassion in judging or punishing. 

pardoning

noun
  • The act by which somebody is pardoned. 

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