legacy vs used-to-be

legacy

adj
  • Left over from the past; no longer current. 

noun
  • The descendant of an alumnus. 

  • Money or property bequeathed to someone in a will. 

  • Something inherited from a predecessor or the past. 

used-to-be

adj
  • Former, ex-. 

How often have the words legacy and used-to-be occurred in a corpus of books? (source: Google Ngram Viewer )