city manager vs prepositus

city manager

noun
  • A municipal official responsible for the operations of a city, usually appointed by a town or city council rather than elected. 

prepositus

noun
  • The presiding officer of various civil bodies. 

  • A provost: the presiding officer of various ecclesiastical bodies. 

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