legwork vs perquisition

legwork

noun
  • Work, especially research or preparation, that involves significant walking, travel, or similar effort. 

  • Skillful or vigorous use of the legs, as in dance or sports. 

perquisition

noun
  • A thorough inquiry or search. 

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