equitability vs impartiality

equitability

noun
  • The quality of being equitable; equitableness. 

  • The extent of the representation by equal numbers of individuals of the different species of a given community. 

impartiality

noun
  • The quality of being impartial; fairness. 

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