bigger vs enhance

bigger

verb
  • To make or become bigger. 

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. 

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