niceness vs subtlety

niceness

noun
  • Pleasantness, especially of behaviour or personality; agreeableness. 

  • 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. 

subtlety

noun
  • The quality of being scarcely noticeable or difficult to discern. 

  • The quality of being done in a clever way that is not obvious or not direct; the quality of being carefully thought out. 

  • The quality of being able to notice or understand things that are not obvious. 

  • An instance of being subtle, a subtle thing, especially a subtle argument or distinction. 

  • The quality of being able to achieve one's aims through clever, delicate or indirect methods. 

  • An ornate medieval illusion dish or table decoration, especially when made from one thing but crafted to look like another. 

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