go-between vs point of contact

go-between

noun
  • An intermediary or middleman. 

  • A shogi piece, used in chu shogi and larger shogi variants, that can move one step straight forward or straight backwards. 

point of contact

noun
  • A person who is associated with a defined Internet entity. 

  • The single person who represents an organization, for a specific task. 

  • A specific intersection; a contact point. 

How often have the words go-between and point of contact occurred in a corpus of books? (source: Google Ngram Viewer )