-91.72% is the change from 640 to 53
Calculation steps:
[( 53 - 640 ) ÷ 640] x 100 = -91.72%
Formula
Percentage change = [(53 - 640) / 640] x 100
Subtract the new number by the original number
53 - 640 = -587
-587 ÷ 640 = -0.9171875
-0.9171875 x 100 = -91.72%