slowness vs subnormality

slowness

noun
  • The quality or state of being slow. 

  • A unit, the reciprocal of velocity, that delineates the amount of time required for an object to travel a given distance. 

subnormality

noun
  • The state or condition of being subnormal. 

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