accrual vs diminishment

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. 

diminishment

noun
  • The act of diminishing; reducing in size, quantity, or quality. 

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