-81.1% is the change from 836 to 158
Calculation steps:
[( 158 - 836 ) ÷ 836] x 100 = -81.1%
Formula
Percentage change = [(158 - 836) / 836] x 100
Subtract the new number by the original number
158 - 836 = -678
-678 ÷ 836 = -0.8110047846889952
-0.8110047846889952 x 100 = -81.1%