There are 2 compenants of the PPA. First, there is the annual compensation credit that is deposited each May, in your case, as you stated is 8%. So you take your calendar earnings from the previous year mulitple by 8% and that should be the amount of your deposit. If you made $75,000 in CY 2020 mulitplied by 8% your deposit in May of 2021 should be $6,000. Then at the end of each quarter you earn 1% of your balance as an interest deposit. If you account balance is 82,551.00 your end of quarter interest deposit would be $825.51, bringing your new balance to $83,376.51, the next quarter your interest deposit would be $833.76 bringing your new balance to $84,210.27 and so on.