come to a stop vs let up

come to a stop

verb
  • To stop moving or being active; to stop. 

  • To reach a point where little progress is being made; to come to an impasse; to stop. 

let up

verb
  • To cease or stop (doing something intense). 

  • To cease or stop. 

How often have the words come to a stop and let up occurred in a corpus of books? (source: Google Ngram Viewer )