40.91% is the change from 220 to 310
Calculation steps:
[( 310 - 220 ) ÷ 220] x 100 = 40.91%
Formula
Percentage change = [(310 - 220) / 220] x 100
Subtract the new number by the original number
310 - 220 = 90
90 ÷ 220 = 0.4090909090909091
0.4090909090909091 x 100 = 40.91%