coldness vs mildness

coldness

noun
  • Limited enthusiasm or affection; coolness. 

  • The sensation resulting from exposure to low temperatures. 

  • The relative lack of heat. 

  • The reciprocal of absolute temperature. 

mildness

noun
  • The quality of being mild; gentleness. 

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