-81.59% is the change from 820 to 151
Calculation steps:
[( 151 - 820 ) ÷ 820] x 100 = -81.59%
Formula
Percentage change = [(151 - 820) / 820] x 100
Subtract the new number by the original number
151 - 820 = -669
-669 ÷ 820 = -0.8158536585365853
-0.8158536585365853 x 100 = -81.59%