fleetness vs immediacy

fleetness

noun
  • The quality of being fleet or swift; rapidity. 

immediacy

noun
  • The quality of being immediate, of happening right away. 

  • Immediate awareness or apprehension. 

  • Lack of mediation; directness. 

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