-89.53% is the change from 640 to 67
Calculation steps:
[( 67 - 640 ) ÷ 640] x 100 = -89.53%
Formula
Percentage change = [(67 - 640) / 640] x 100
Subtract the new number by the original number
67 - 640 = -573
-573 ÷ 640 = -0.8953125
-0.8953125 x 100 = -89.53%