-3.96% is the change from 530 to 509
Calculation steps:
[( 509 - 530 ) ÷ 530] x 100 = -3.96%
Formula
Percentage change = [(509 - 530) / 530] x 100
Subtract the new number by the original number
509 - 530 = -21
-21 ÷ 530 = -0.03962264150943396
-0.03962264150943396 x 100 = -3.96%