-1.91% is the change from 839 to 823
Calculation steps:
[( 823 - 839 ) ÷ 839] x 100 = -1.91%
Formula
Percentage change = [(823 - 839) / 839] x 100
Subtract the new number by the original number
823 - 839 = -16
-16 ÷ 839 = -0.01907032181168057
-0.01907032181168057 x 100 = -1.91%