68.52% is the change from 270 to 455
Calculation steps:
[( 455 - 270 ) ÷ 270] x 100 = 68.52%
Formula
Percentage change = [(455 - 270) / 270] x 100
Subtract the new number by the original number
455 - 270 = 185
185 ÷ 270 = 0.6851851851851852
0.6851851851851852 x 100 = 68.52%