728.4% is the change from 81 to 671
Calculation steps:
[( 671 - 81 ) ÷ 81] x 100 = 728.4%
Formula
Percentage change = [(671 - 81) / 81] x 100
Subtract the new number by the original number
671 - 81 = 590
590 ÷ 81 = 7.283950617283951
7.283950617283951 x 100 = 728.4%