headquarters vs home base

headquarters

noun
  • The center of an organization's operations or administration. 

  • The military installation from which troops are commanded and orders are issued; the military unit consisting of a commander and his support staff. 

  • A place of concentrated activity or influence. 

home base

noun
  • headquarters 

  • home plate 

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