-84.06% is the change from 991 to 158
Calculation steps:
[( 158 - 991 ) ÷ 991] x 100 = -84.06%
Formula
Percentage change = [(158 - 991) / 991] x 100
Subtract the new number by the original number
158 - 991 = -833
-833 ÷ 991 = -0.8405650857719476
-0.8405650857719476 x 100 = -84.06%