captive vs under restraint

captive

adj
  • Subdued by love; charmed; captivated. 

  • Of or relating to bondage or confinement; serving to confine. 

  • Held prisoner; not free; confined. 

noun
  • One charmed or subdued by beauty, excellence, or affection; one who is captivated. 

  • One who has been captured or is otherwise confined. 

  • One held prisoner. 

under restraint

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