procurator vs successor

procurator

noun
  • An agent or attorney. 

  • A tax collector. 

  • The governor of a small imperial province. 

  • A legal officer who both investigates and prosecutes crimes, found in some inquisitorial legal systems, particularly communist or formerly communist states – see public procurator 

successor

noun
  • A person who inherits a title or office. 

  • The next heir in order or succession. 

  • A person or thing that immediately follows another in holding an office or title. 

  • The integer, ordinal number or cardinal number immediately following another. 

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