-54.55% is the change from 220 to 100
Calculation steps:
[( 100 - 220 ) ÷ 220] x 100 = -54.55%
Formula
Percentage change = [(100 - 220) / 220] x 100
Subtract the new number by the original number
100 - 220 = -120
-120 ÷ 220 = -0.5454545454545454
-0.5454545454545454 x 100 = -54.55%