81.6% is the change from 424 to 770
Calculation steps:
[( 770 - 424 ) ÷ 424] x 100 = 81.6%
Formula
Percentage change = [(770 - 424) / 424] x 100
Subtract the new number by the original number
770 - 424 = 346
346 ÷ 424 = 0.8160377358490566
0.8160377358490566 x 100 = 81.6%