697.53% is the change from 81 to 646
Calculation steps:
[( 646 - 81 ) ÷ 81] x 100 = 697.53%
Formula
Percentage change = [(646 - 81) / 81] x 100
Subtract the new number by the original number
646 - 81 = 565
565 ÷ 81 = 6.9753086419753085
6.9753086419753085 x 100 = 697.53%