56.77% is the change from 421 to 660
Calculation steps:
[( 660 - 421 ) ÷ 421] x 100 = 56.77%
Formula
Percentage change = [(660 - 421) / 421] x 100
Subtract the new number by the original number
660 - 421 = 239
239 ÷ 421 = 0.5676959619952494
0.5676959619952494 x 100 = 56.77%