-71.88% is the change from 64 to 18
Calculation steps:
[( 18 - 64 ) ÷ 64] x 100 = -71.88%
Formula
Percentage change = [(18 - 64) / 64] x 100
Subtract the new number by the original number
18 - 64 = -46
-46 ÷ 64 = -0.71875
-0.71875 x 100 = -71.88%
Example