childhood vs upgrowth

childhood

noun
  • The early stages of development of something. 

  • The state of being a child. 

  • The time during which one is a child, from between infancy and puberty. 

upgrowth

noun
  • The process or result of growing up; progress; development. 

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