mercifulness vs tenderness

mercifulness

noun
  • The state of being merciful; mercy. 

tenderness

noun
  • a tendency to express warm, compassionate feelings 

  • pain or discomfort when an affected area is touched 

  • concern for the feelings or welfare of others 

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