-87.7% is the change from 813 to 100
Calculation steps:
[( 100 - 813 ) ÷ 813] x 100 = -87.7%
Formula
Percentage change = [(100 - 813) / 813] x 100
Subtract the new number by the original number
100 - 813 = -713
-713 ÷ 813 = -0.8769987699876999
-0.8769987699876999 x 100 = -87.7%