burgomaster vs chancellor

burgomaster

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

chancellor

noun
  • The head of the government in some German-speaking countries. 

  • The head of a university, sometimes purely ceremonial. 

  • The chief judge of a court of chancery (that is, one exercising equity jurisdiction). 

  • A senior secretary or official with administrative or legal duties, sometimes in charge of some area of government such as finance or justice. 

  • A senior record keeper of a cathedral; a senior legal officer for a bishop or diocese in charge of hearing cases involving ecclesiastical law. 

  • The foreman of a jury. 

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