-20% is the change from 815 to 652
Calculation steps:
[( 652 - 815 ) ÷ 815] x 100 = -20%
Formula
Percentage change = [(652 - 815) / 815] x 100
Subtract the new number by the original number
652 - 815 = -163
-163 ÷ 815 = -0.2
-0.2 x 100 = -20%
Example