nest egg vs trove

nest egg

noun
  • A saving; a reserve of money. 

  • A natural or artificial egg placed in a bird's nest, to encourage the bird to lay its own eggs there. 

  • An egg squash. 

trove

noun
  • A treasure trove; a collection of treasure. 

  • A collection of things. 

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