burgomaster vs prefect

burgomaster

noun
  • The mayor, or head magistrate, of a town in the Netherlands, Belgium, Germany and certain other countries. 

prefect

noun
  • The head of a county in Albania or Romania. 

  • The head of a department in France. 

  • A school pupil in a position of power over other pupils. 

  • A commander. 

  • An official of Ancient Rome who controlled or superintended a particular command, charge, department, etc. 

  • The head of a prefecture in Japan. 

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