postpone vs put back

postpone

verb
  • To delay or put off an event, appointment, etc. 

put back

verb
  • To postpone an arranged event or appointment. 

  • To turn back; to return. 

  • To change the time in a time zone to an earlier time. 

  • To return something to its original place. 

  • To drink fast; to knock down alcohol. 

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