reintroduction vs rejuvenation

reintroduction

noun
  • the act of introducing something again, especially the release of animals from captivity into the wild 

rejuvenation

noun
  • The process of producing beneficial changes. 

  • The process of rendering young again. 

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