hinder vs strengthen

hinder

verb
  • To make difficult to accomplish; to act as an obstacle; to frustrate. 

  • To delay or impede; to keep back, to prevent. 

adj
  • Of or belonging to that part or end which is in the rear or hind, or which follows. 

noun
  • The buttocks. 

strengthen

verb
  • To empower; to give moral strength to; to encourage; to enhearten. 

  • To make strong or stronger; to add strength to; to increase the strength of; to fortify. 

  • To reinforce, to add to, to support (someone or something) 

  • To grow strong or stronger. 

  • To substantiate; to corroborate (a belief, argument, etc.) 

  • To augment; to improve; to intensify. 

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