-4.71% is the change from 85 to 81
Calculation steps:
[( 81 - 85 ) ÷ 85] x 100 = -4.71%
Formula
Percentage change = [(81 - 85) / 85] x 100
Subtract the new number by the original number
81 - 85 = -4
-4 ÷ 85 = -0.047058823529411764
-0.047058823529411764 x 100 = -4.71%