-20.12% is the change from 820 to 655
Calculation steps:
[( 655 - 820 ) ÷ 820] x 100 = -20.12%
Formula
Percentage change = [(655 - 820) / 820] x 100
Subtract the new number by the original number
655 - 820 = -165
-165 ÷ 820 = -0.20121951219512196
-0.20121951219512196 x 100 = -20.12%