old sport vs sugar-plum

old sport

noun
  • A term of endearment used to a friend. 

sugar-plum

noun
  • Term of endearment: sweetheart, darling. 

  • A round or oval sweet/piece of candy made of boiled sugar. 

How often have the words old sport and sugar-plum occurred in a corpus of books? (source: Google Ngram Viewer )