839.39% is the change from 66 to 620
Calculation steps:
[( 620 - 66 ) ÷ 66] x 100 = 839.39%
Formula
Percentage change = [(620 - 66) / 66] x 100
Subtract the new number by the original number
620 - 66 = 554
554 ÷ 66 = 8.393939393939394
8.393939393939394 x 100 = 839.39%