-90.11% is the change from 839 to 83
Calculation steps:
[( 83 - 839 ) ÷ 839] x 100 = -90.11%
Formula
Percentage change = [(83 - 839) / 839] x 100
Subtract the new number by the original number
83 - 839 = -756
-756 ÷ 839 = -0.901072705601907
-0.901072705601907 x 100 = -90.11%