-85.94% is the change from 64 to 9
Calculation steps:
[( 9 - 64 ) ÷ 64] x 100 = -85.94%
Formula
Percentage change = [(9 - 64) / 64] x 100
Subtract the new number by the original number
9 - 64 = -55
-55 ÷ 64 = -0.859375
-0.859375 x 100 = -85.94%
Example