-64.71% is the change from 85 to 30
Calculation steps:
[( 30 - 85 ) ÷ 85] x 100 = -64.71%
Formula
Percentage change = [(30 - 85) / 85] x 100
Subtract the new number by the original number
30 - 85 = -55
-55 ÷ 85 = -0.6470588235294118
-0.6470588235294118 x 100 = -64.71%