ebb tide vs plummet

ebb tide

noun
  • The period between high tide and the next low tide in which the sea is receding. 

plummet

noun
  • A decline; a fall; a drop. 

  • A violent or dramatic fall. 

verb
  • To drop swiftly, in a direct manner; to fall quickly. 

How often have the words ebb tide and plummet occurred in a corpus of books? (source: Google Ngram Viewer )