assignee vs inheritor

assignee

noun
  • one to whom a thing is assigned 

  • one to whom rights or property is being transferred 

  • one who is appointed to act or speak in place of another; an agent 

inheritor

noun
  • Someone who inherits something; an heir. 

  • A class, etc. that derives from another code element through inheritance. 

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