preadolescence vs prepubescence

preadolescence

noun
  • The period between childhood and adolescence, between the ages of about 9 and 11 for girls, and 10 and 12 for boys. 

prepubescence

noun
  • The period prior to the onset of puberty; prepuberty 

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