calisthenics vs floor exercise

calisthenics

noun
  • A system of such exercises. 

  • Gymnastic exercises under the participation of a (surface-wise) multitude of muscles and often minimal equipment (thus, usually bodyweight exercises) with a stress on stamina. 

floor exercise

noun
  • A performance on a mat-covered floor using no apparatus. 

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