-0.24% is the change from 820 to 818
Calculation steps:
[( 818 - 820 ) ÷ 820] x 100 = -0.24%
Formula
Percentage change = [(818 - 820) / 820] x 100
Subtract the new number by the original number
818 - 820 = -2
-2 ÷ 820 = -0.0024390243902439024
-0.0024390243902439024 x 100 = -0.24%