gentlewoman vs grand dukedom

gentlewoman

noun
  • A woman of the nobility. 

  • A female member of a legislature, especially a female member of a House of Representatives. 

grand dukedom

noun
  • The title of grand duke or grand duchess, with its pertaining privileges and obligations; contrast grand duchy. 

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