-83.89% is the change from 509 to 82
Calculation steps:
[( 82 - 509 ) ÷ 509] x 100 = -83.89%
Formula
Percentage change = [(82 - 509) / 509] x 100
Subtract the new number by the original number
82 - 509 = -427
-427 ÷ 509 = -0.8388998035363457
-0.8388998035363457 x 100 = -83.89%