-18.52% is the change from 270 to 220
Calculation steps:
[( 220 - 270 ) ÷ 270] x 100 = -18.52%
Formula
Percentage change = [(220 - 270) / 270] x 100
Subtract the new number by the original number
220 - 270 = -50
-50 ÷ 270 = -0.18518518518518517
-0.18518518518518517 x 100 = -18.52%