compelling vs constraining

compelling

noun
  • An act of compulsion; an obliging somebody to do something. 

adj
  • Strongly or irresistibly evoking interest or attention. 

  • Forceful. 

constraining

noun
  • The act by which something is constrained. 

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