income vs protection money

income

noun
  • Money one earns by working or by capitalising on the work of others. 

  • A disease or ailment without known or apparent cause, as distinguished from one induced by accident or contagion; an oncome. 

  • That which is taken into the body as food; the ingesta; sometimes restricted to the nutritive, or digestible, portion of the food. 

  • Money coming in to a fund, account, or policy. 

protection money

noun
  • Money paid, especially at regular intervals, to criminals or to corrupt officials who threaten to cause harm to the payer or to his or her business if the money is not paid. 

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