life savings vs nest egg

life savings

noun
  • A large sum of money one has saved over a considerable number of years. 

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. 

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