teenage vs underage

teenage

adj
  • Of or relating to an age between thirteen and nineteen years old. 

underage

adj
  • Below the legal age for some activity, such as drinking or having sex. 

  • Not yet a legal adult; still a minor. 

noun
  • A deficit or shortfall in funds, inventory, or capacity. 

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