-19.93% is the change from 828 to 663
Calculation steps:
[( 663 - 828 ) ÷ 828] x 100 = -19.93%
Formula
Percentage change = [(663 - 828) / 828] x 100
Subtract the new number by the original number
663 - 828 = -165
-165 ÷ 828 = -0.19927536231884058
-0.19927536231884058 x 100 = -19.93%