How do I enter my Arizona Charitable Foster Care Organization Contributions Credit carryover?

For each taxable year, enter the amount of credit you originally computed in the Original Credit Amount column. Then enter the total carryover amount you've claimed from that credit in the Amount Previously Used column.

You may claim a carryover only for the portion of the credit that you didn't apply to tax. You can't claim a carryover for any amount you gave that was more than the maximum amount allowed as a credit in that year.

How do I calculate my credit carryover for each year?