-83.93% is the change from 971 to 156
Calculation steps:
[( 156 - 971 ) ÷ 971] x 100 = -83.93%
Formula
Percentage change = [(156 - 971) / 971] x 100
Subtract the new number by the original number
156 - 971 = -815
-815 ÷ 971 = -0.839340885684861
-0.839340885684861 x 100 = -83.93%