mixed-race vs underbred

mixed-race

adj
  • Having genetic characteristics of two or more different races. 

underbred

adj
  • Not purebred; of an inferior strain. 

  • Of inferior breeding or upbringing; vulgar, lacking in manners or finesse. 

How often have the words mixed-race and underbred occurred in a corpus of books? (source: Google Ngram Viewer )