step on vs trample

step on

verb
  • Used other than figuratively or idiomatically: see step, on. 

  • to adulterate a drug for the purpose of increasing its bulk, and therefore its profit; to dilute, cut. 

trample

verb
  • To crush something by walking on it. 

  • To treat someone harshly. 

  • To walk heavily and destructively. 

  • To cause emotional injury as if by trampling. 

noun
  • A heavy stepping. 

  • The sound of heavy footsteps. 

How often have the words step on and trample occurred in a corpus of books? (source: Google Ngram Viewer )