darling vs the object of one's affections

darling

noun
  • A kind or sweet person; sweetheart. 

  • An affectionate term of address. 

  • A person or thing very popular with a certain group. 

  • A person who is dear to one. 

adj
  • Dear; cherished. 

  • charming 

the object of one's affections

How often have the words darling and the object of one's affections occurred in a corpus of books? (source: Google Ngram Viewer )