in a (flat) spin vs relaxed

in a (flat) spin

relaxed

adj
  • Without physical tension; in a state of equilibrium. 

  • Made more lenient; less strict; lax. 

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

  • Of a muscle: soft, not tensed. 

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