-24.71% is the change from 85 to 64
Calculation steps:
[( 64 - 85 ) ÷ 85] x 100 = -24.71%
Formula
Percentage change = [(64 - 85) / 85] x 100
Subtract the new number by the original number
64 - 85 = -21
-21 ÷ 85 = -0.24705882352941178
-0.24705882352941178 x 100 = -24.71%