-87.63% is the change from 800 to 99
Calculation steps:
[( 99 - 800 ) ÷ 800] x 100 = -87.63%
Formula
Percentage change = [(99 - 800) / 800] x 100
Subtract the new number by the original number
99 - 800 = -701
-701 ÷ 800 = -0.87625
-0.87625 x 100 = -87.63%