niceness vs unkindness

niceness

noun
  • A value determining how much processor time to concede to a running process. (See also nice (verb), renice.) 

  • Effeminacy; indulgence in soft living or luxuriousness. 

  • Fastidiousness; fine sensitivity. 

  • Pleasantness, especially of behaviour or personality; agreeableness. 

unkindness

noun
  • The state or quality of being unkind. 

  • An unkind act. 

  • The collective noun for ravens 

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