81.85% is the change from 270 to 491
Calculation steps:
[( 491 - 270 ) ÷ 270] x 100 = 81.85%
Formula
Percentage change = [(491 - 270) / 270] x 100
Subtract the new number by the original number
491 - 270 = 221
221 ÷ 270 = 0.8185185185185185
0.8185185185185185 x 100 = 81.85%