-50.91% is the change from 550 to 270
Calculation steps:
[( 270 - 550 ) ÷ 550] x 100 = -50.91%
Formula
Percentage change = [(270 - 550) / 550] x 100
Subtract the new number by the original number
270 - 550 = -280
-280 ÷ 550 = -0.509090909090909
-0.509090909090909 x 100 = -50.91%