digging vs paleohistory

digging

noun
  • The action performed by a person or thing that digs. 

  • A place where ore is dug, especially certain localities in California, Australia, etc. where gold is obtained. 

paleohistory

noun
  • Synonym of archaeology 

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