dear heart vs sweet pea

dear heart

noun
  • Term of affection; sweetheart. 

sweet pea

noun
  • A term of endearment for something sweet or lovely; a child or an intimate partner, for example. 

  • A flowering plant, Lathyrus odoratus, grown for its bright colours and sweet fragrance. 

How often have the words dear heart and sweet pea occurred in a corpus of books? (source: Google Ngram Viewer )