presentational vs unrepresentative

presentational

noun
  • A clause using existential "there" with a verb other than a form of "be", as in "There followed a brief silence". 

adj
  • Of, or pertaining to, presentation(s). 

unrepresentative

adj
  • Not representative 

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