duress vs necessitation

duress

noun
  • Restraint in which a person is influenced, whether by lawful or unlawful forceful compulsion of their liberty by monition or implementation of physical enforcement; legally for the incurring of civil liability, of a citizen's arrest, or of subrogation, or illegally for the committing of an offense, of forcing a contract, or of using threats. 

  • Constraint by threat. 

verb
  • To put under duress; to pressure. 

necessitation

noun
  • Necessity, understood as a logical or other philosophical principle, or as a law or force of nature. 

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