mildness vs moderation

mildness

noun
  • The quality of being mild; gentleness. 

moderation

noun
  • The state or quality of being moderate; avoidance of extremes 

  • An instance of moderating: bringing something away from extremes, especially in a beneficial way 

  • The process of moderating a discussion 

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