-3.64% is the change from 550 to 530
Calculation steps:
[( 530 - 550 ) ÷ 550] x 100 = -3.64%
Formula
Percentage change = [(530 - 550) / 550] x 100
Subtract the new number by the original number
530 - 550 = -20
-20 ÷ 550 = -0.03636363636363636
-0.03636363636363636 x 100 = -3.64%