-38.17% is the change from 131 to 81
Calculation steps:
[( 81 - 131 ) ÷ 131] x 100 = -38.17%
Formula
Percentage change = [(81 - 131) / 131] x 100
Subtract the new number by the original number
81 - 131 = -50
-50 ÷ 131 = -0.3816793893129771
-0.3816793893129771 x 100 = -38.17%