constrain vs contain

constrain

verb
  • To keep within close bounds; to confine. 

  • To force physically, by strong persuasion or pressuring; to compel; to oblige. 

  • To reduce a result in response to limited resources. 

contain

verb
  • To put constraints upon; to restrain; to confine; to keep within bounds. 

  • To include as a part. 

  • To hold inside. 

  • To have as an element or subset. 

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