accrual vs income

accrual

noun
  • An increase; something that accumulates, especially an amount of money that periodically accumulates for a specific purpose 

  • from the creditor's viewpoint, a charge incurred in one accounting period that has not been, but is to be, paid by the end of it. 

income

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

  • 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. 

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