3.58% is the change from 531 to 550
Calculation steps:
[( 550 - 531 ) ÷ 531] x 100 = 3.58%
Formula
Percentage change = [(550 - 531) / 531] x 100
Subtract the new number by the original number
550 - 531 = 19
19 ÷ 531 = 0.035781544256120526
0.035781544256120526 x 100 = 3.58%