antediluvian vs past its prime

antediluvian

noun
  • One who lived prior to Noah's Flood. 

adj
  • Ancient or antiquated. 

  • Extremely dated. 

  • Pertaining or belonging to the time period prior to a great or destructive flood or deluge. 

  • Pertaining or belonging to the time prior to Noah's Flood. 

past its prime

How often have the words antediluvian and past its prime occurred in a corpus of books? (source: Google Ngram Viewer )