939.39% is the change from 66 to 686
Calculation steps:
[( 686 - 66 ) ÷ 66] x 100 = 939.39%
Formula
Percentage change = [(686 - 66) / 66] x 100
Subtract the new number by the original number
686 - 66 = 620
620 ÷ 66 = 9.393939393939394
9.393939393939394 x 100 = 939.39%