chill out vs stand down

chill out

verb
  • To relax or take time out; to calm down. 

stand down

verb
  • To wait; to stop pursuing, stop fighting, or relax from a heightened readiness posture. 

  • To withdraw or retire from a position or from a team. 

How often have the words chill out and stand down occurred in a corpus of books? (source: Google Ngram Viewer )