-87.82% is the change from 813 to 99
Calculation steps:
[( 99 - 813 ) ÷ 813] x 100 = -87.82%
Formula
Percentage change = [(99 - 813) / 813] x 100
Subtract the new number by the original number
99 - 813 = -714
-714 ÷ 813 = -0.8782287822878229
-0.8782287822878229 x 100 = -87.82%