-82.91% is the change from 509 to 87
Calculation steps:
[( 87 - 509 ) ÷ 509] x 100 = -82.91%
Formula
Percentage change = [(87 - 509) / 509] x 100
Subtract the new number by the original number
87 - 509 = -422
-422 ÷ 509 = -0.8290766208251473
-0.8290766208251473 x 100 = -82.91%