accrual vs addition

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. 

addition

noun
  • The act of adding anything. 

  • The arithmetic operation of adding. 

  • A dot at the right side of a note as an indication that its sound is to be lengthened one half. 

  • Anything that is added. 

  • A title annexed to a person's name to identify him or her more precisely. 

  • Something added to a coat of arms, as a mark of honour. 

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