-16.1% is the change from 1000 to 839
Calculation steps:
[( 839 - 1000 ) ÷ 1000] x 100 = -16.1%
Formula
Percentage change = [(839 - 1000) / 1000] x 100
Subtract the new number by the original number
839 - 1000 = -161
-161 ÷ 1000 = -0.161
-0.161 x 100 = -16.1%