drop in the sea vs peppercorn

drop in the sea

noun
  • A very small or insignificant amount; something of little importance. 

peppercorn

noun
  • A small, insignificant quantity; a whit or jot. 

  • A nominal consideration used to satisfy the requirements for the creation of a legal contract. 

  • The seeds of the plant Piper nigrum. Commonly used as a spice, usually but not always ground or crushed. 

How often have the words drop in the sea and peppercorn occurred in a corpus of books? (source: Google Ngram Viewer )