-20.78% is the change from 818 to 648
Calculation steps:
[( 648 - 818 ) ÷ 818] x 100 = -20.78%
Formula
Percentage change = [(648 - 818) / 818] x 100
Subtract the new number by the original number
648 - 818 = -170
-170 ÷ 818 = -0.2078239608801956
-0.2078239608801956 x 100 = -20.78%