-6.91% is the change from 550 to 512
Calculation steps:
[( 512 - 550 ) ÷ 550] x 100 = -6.91%
Formula
Percentage change = [(512 - 550) / 550] x 100
Subtract the new number by the original number
512 - 550 = -38
-38 ÷ 550 = -0.06909090909090909
-0.06909090909090909 x 100 = -6.91%