-83.69% is the change from 509 to 83
Calculation steps:
[( 83 - 509 ) ÷ 509] x 100 = -83.69%
Formula
Percentage change = [(83 - 509) / 509] x 100
Subtract the new number by the original number
83 - 509 = -426
-426 ÷ 509 = -0.8369351669941061
-0.8369351669941061 x 100 = -83.69%