-81.73% is the change from 509 to 93
Calculation steps:
[( 93 - 509 ) ÷ 509] x 100 = -81.73%
Formula
Percentage change = [(93 - 509) / 509] x 100
Subtract the new number by the original number
93 - 509 = -416
-416 ÷ 509 = -0.8172888015717092
-0.8172888015717092 x 100 = -81.73%