-81.83% is the change from 820 to 149
Calculation steps:
[( 149 - 820 ) ÷ 820] x 100 = -81.83%
Formula
Percentage change = [(149 - 820) / 820] x 100
Subtract the new number by the original number
149 - 820 = -671
-671 ÷ 820 = -0.8182926829268292
-0.8182926829268292 x 100 = -81.83%