puberty vs young days

puberty

noun
  • The process of sexual development that produces secondary sex characteristics and makes a person capable of reproducing sexually. 

  • The period when a plant begins to flower. 

  • A developmental phase brought about by the action of hormones as part of the maturing process. For humans, there are three in total. 

  • The age at which a person is first capable of sexual reproduction. 

young days

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