-90.21% is the change from 817 to 80
Calculation steps:
[( 80 - 817 ) ÷ 817] x 100 = -90.21%
Formula
Percentage change = [(80 - 817) / 817] x 100
Subtract the new number by the original number
80 - 817 = -737
-737 ÷ 817 = -0.9020807833537332
-0.9020807833537332 x 100 = -90.21%