686.42% is the change from 81 to 637
Calculation steps:
[( 637 - 81 ) ÷ 81] x 100 = 686.42%
Formula
Percentage change = [(637 - 81) / 81] x 100
Subtract the new number by the original number
637 - 81 = 556
556 ÷ 81 = 6.864197530864198
6.864197530864198 x 100 = 686.42%