promote vs retard

promote

verb
  • To encourage, urge or incite. 

  • To increase the activity of (a catalyst) by changing its surface structure. 

  • To elevate to a higher league. 

  • To raise (someone) to a more important, responsible, or remunerative job or rank. 

  • To move on to a subsequent stage of education. 

  • To advocate or urge on behalf of (something or someone); to attempt to popularize or sell by means of advertising or publicity. 

  • To exchange (a pawn) for a queen or other piece when it reaches the eighth rank. 

retard

verb
  • To put off; to postpone. 

  • To decelerate; to slow down. 

  • To keep delaying; to continue to hinder; to prevent from progressing. 

noun
  • Retardation; delay. 

  • A slowing down of the tempo; a ritardando. 

  • A person or being who is extremely stupid or slow to learn. 

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