-85.66% is the change from 509 to 73
Calculation steps:
[( 73 - 509 ) ÷ 509] x 100 = -85.66%
Formula
Percentage change = [(73 - 509) / 509] x 100
Subtract the new number by the original number
73 - 509 = -436
-436 ÷ 509 = -0.8565815324165029
-0.8565815324165029 x 100 = -85.66%