fine-tooth comb vs foraging

fine-tooth comb

noun
  • A means of making a thorough search. 

  • A comb with fine, closely spaced teeth, especially one used for removing head lice and their nits (eggs) from the hair; a nit comb. 

verb
  • To search (something or somewhere) meticulously. 

foraging

noun
  • The act of searching for food. 

How often have the words fine-tooth comb and foraging occurred in a corpus of books? (source: Google Ngram Viewer )