-71.86% is the change from 821 to 231
Calculation steps:
[( 231 - 821 ) ÷ 821] x 100 = -71.86%
Formula
Percentage change = [(231 - 821) / 821] x 100
Subtract the new number by the original number
231 - 821 = -590
-590 ÷ 821 = -0.7186358099878197
-0.7186358099878197 x 100 = -71.86%