-89.79% is the change from 999 to 102
Calculation steps:
[( 102 - 999 ) ÷ 999] x 100 = -89.79%
Formula
Percentage change = [(102 - 999) / 999] x 100
Subtract the new number by the original number
102 - 999 = -897
-897 ÷ 999 = -0.8978978978978979
-0.8978978978978979 x 100 = -89.79%