improve vs thrive

improve

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

  • To become better. 

thrive

verb
  • To increase in wealth or success; to prosper, be profitable. 

  • To grow or increase stature; to grow vigorously or luxuriantly, to flourish. 

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