as fit as a flea vs healthy

as fit as a flea

healthy

adj
  • Enjoying good health; well; free from disease or disorder. 

  • Conducive to health. 

  • Evincing health. 

  • Significant, hefty; beneficial. 

How often have the words as fit as a flea and healthy occurred in a corpus of books? (source: Google Ngram Viewer )