fire brigade vs membership

fire brigade

noun
  • A group of people within a corporation or industrial site, organized for the purpose of putting out fires, usually in addition to their normal job. 

  • An organization, often part of a local government, whose purpose is preventing and putting out fires. 

  • A trained unit that can be rapidly deployed to deal with any difficult situation. 

membership

noun
  • The body of members of an organization. 

  • The state of being a member of a group or organization. 

  • The fact of being a member of a set. 

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