duologue vs interlocution

duologue

noun
  • A conversation between two persons; dialogue. 

  • A dramatic performance or piece in the form of a dialogue limited to two speakers. 

interlocution

noun
  • Discussion or conversation. 

  • An intermediate decree before final decision. 

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