-84.87% is the change from 509 to 77
Calculation steps:
[( 77 - 509 ) ÷ 509] x 100 = -84.87%
Formula
Percentage change = [(77 - 509) / 509] x 100
Subtract the new number by the original number
77 - 509 = -432
-432 ÷ 509 = -0.8487229862475442
-0.8487229862475442 x 100 = -84.87%