occlude vs restrain

occlude

verb
  • To obstruct, cover, or otherwise block (an opening, a portion of an image, etc.). 

  • To absorb, as a gas by a metal. 

restrain

verb
  • To restrict or limit. 

  • To control or keep in check. 

  • To deprive of liberty. 

  • To strain again. 

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