-28.1% is the change from 306 to 220
Calculation steps:
[( 220 - 306 ) ÷ 306] x 100 = -28.1%
Formula
Percentage change = [(220 - 306) / 306] x 100
Subtract the new number by the original number
220 - 306 = -86
-86 ÷ 306 = -0.28104575163398693
-0.28104575163398693 x 100 = -28.1%