extensity vs gamut

extensity

noun
  • The degree to which something is extensive 

  • The state of being extensive or of having extension 

gamut

noun
  • A (normally) complete range. 

  • All the notes in a musical scale. 

  • All the colours that can be presented by a device such as a monitor or printer. 

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