Pivot Table showing Difference From different field for the Previous Year

[alex1alex]

Hi All,
Given this table put into a Pivot Table.....

How would I show, for 2021 Requirement value, the between 2021 Requirement and the 2020 Actual?
So, 12 - 10 = 2

Generally, I'm try to show next years requirement value against this year's actual value.
(there a lots of other fruits in the real table )

Thanks very much,
Alex