-90.78% is the change from 640 to 59
Calculation steps:
[( 59 - 640 ) ÷ 640] x 100 = -90.78%
Formula
Percentage change = [(59 - 640) / 640] x 100
Subtract the new number by the original number
59 - 640 = -581
-581 ÷ 640 = -0.9078125
-0.9078125 x 100 = -90.78%