circle back vs reenter

circle back

verb
  • To return to a previous location or state; to come back to. 

  • To return to a previous topic of discussion; to bring up again. 

  • Used other than figuratively or idiomatically: see circle, back. 

reenter

verb
  • To enter again; return into. 

  • To enter again; retype, reinput. 

  • To cut deeper where the aqua fortis has not bitten sufficiently. 

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