jigsaw vs mare's nest

jigsaw

noun
  • A jigsaw puzzle. 

  • Something that can be compared to a jigsaw puzzle. 

  • A power saw with fine teeth and a narrow blade which can cut curves in wood or metal. 

verb
  • To cut something using a jigsaw. 

mare's nest

noun
  • A confused or complicated situation; a muddle. 

  • A great discovery which turns out to be illusory; a hoax. 

How often have the words jigsaw and mare's nest occurred in a corpus of books? (source: Google Ngram Viewer )