doubling vs progression

doubling

noun
  • The act of turning around, or doubling back. 

  • A pleat or fold. 

  • The process or an instance of making something double; a multiplication by two. 

progression

noun
  • The act of moving from one thing to another. 

  • A sequence obtained by adding or multiplying each term by a constant. 

  • chord progression 

  • The act of moving forward or proceeding in a course; motion onward. 

  • Development, increase, evolution. 

  • The making an exercise more exerting by manipulating the details of its performance like loaded weight, range of motion, angle, speed. 

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