-81.61% is the change from 821 to 151
Calculation steps:
[( 151 - 821 ) ÷ 821] x 100 = -81.61%
Formula
Percentage change = [(151 - 821) / 821] x 100
Subtract the new number by the original number
151 - 821 = -670
-670 ÷ 821 = -0.8160779537149817
-0.8160779537149817 x 100 = -81.61%