grow up vs upgrow

grow up

verb
  • To stop acting as or like a child (often used as an imperative interjection). 

  • To mature and become an adult. 

  • To start to develop; to flourish. 

intj
  • Used to criticize childish behavior, especially that considered unreasonable for one's age. 

upgrow

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