case officer vs manager

case officer

noun
  • A person assigned to manage a client's affairs. 

  • In intelligence organisations, a person who manages a network of agents. 

manager

noun
  • A person whose job is to manage something, such as a business, a restaurant, or a sports team. 

  • An administrator, for a singer or group. 

  • A window or application whose purpose is to give the user the control over some aspect of the system. 

  • The head coach. 

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