gratuity vs pittance

gratuity

noun
  • An additional payment given freely as thanks for service. 

pittance

noun
  • A meagre allowance of money or wages. 

  • A small amount. 

  • A small allowance of food and drink; a scanty meal. 

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