enhance vs reinforce

enhance

verb
  • To augment or make something greater. 

  • To take up contrast agent (for an organ, tissue, or lesion). 

  • To improve something by adding features. 

  • To be raised up; to grow larger. 

reinforce

verb
  • To strengthen, especially by addition or augmentation. 

  • To emphasize or review. 

  • To encourage (a behavior or idea) through repeated stimulus. 

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