cast about vs track down

cast about

verb
  • To try to find; look around; search. 

  • To plan; plot; contrive. 

track down

verb
  • To hunt for or locate; to search for; to find. 

  • Used other than figuratively or idiomatically: see track, down. 

How often have the words cast about and track down occurred in a corpus of books? (source: Google Ngram Viewer )