-79.9% is the change from 821 to 165
Calculation steps:
[( 165 - 821 ) ÷ 821] x 100 = -79.9%
Formula
Percentage change = [(165 - 821) / 821] x 100
Subtract the new number by the original number
165 - 821 = -656
-656 ÷ 821 = -0.7990255785627284
-0.7990255785627284 x 100 = -79.9%