pain-free vs relaxed

pain-free

adj
  • without pain, free of pain. 

relaxed

adj
  • Free from tension or anxiety; at ease; leisurely. 

  • Without physical tension; in a state of equilibrium. 

  • Made more lenient; less strict; lax. 

  • Of a muscle: soft, not tensed. 

How often have the words pain-free and relaxed occurred in a corpus of books? (source: Google Ngram Viewer )