-83.43% is the change from 821 to 136
Calculation steps:
[( 136 - 821 ) ÷ 821] x 100 = -83.43%
Formula
Percentage change = [(136 - 821) / 821] x 100
Subtract the new number by the original number
136 - 821 = -685
-685 ÷ 821 = -0.8343483556638246
-0.8343483556638246 x 100 = -83.43%