ebb tide vs neap tide

ebb tide

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

neap tide

noun
  • The tide which occurs just after the first and third quarters of the moon, when there is least difference between high tide and low tide. 

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