-51.36% is the change from 331 to 161
Calculation steps:
[( 161 - 331 ) ÷ 331] x 100 = -51.36%
Formula
Percentage change = [(161 - 331) / 331] x 100
Subtract the new number by the original number
161 - 331 = -170
-170 ÷ 331 = -0.513595166163142
-0.513595166163142 x 100 = -51.36%