hinder vs improve

hinder

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

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

noun
  • The buttocks. 

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

improve

verb
  • To make (something) better; to increase the value or productivity (of something). 

  • To become better. 

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