improve vs shrivel

improve

verb
  • To become better. 

  • To make (something) better; to increase the value or productivity (of something). 

shrivel

verb
  • To become wrinkled. 

  • To collapse inward; to crumble. 

  • To draw into wrinkles. 

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