herein vs too

herein

adv
  • In this; within this content, context, or thing. 

too

adv
  • Also; in addition. 

  • Used to contradict a negative assertion. 

  • To an excessive degree; over; more than enough. 

  • Likewise. 

  • To a high degree, very. 

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