-92.97% is the change from 640 to 45
Calculation steps:
[( 45 - 640 ) ÷ 640] x 100 = -92.97%
Formula
Percentage change = [(45 - 640) / 640] x 100
Subtract the new number by the original number
45 - 640 = -595
-595 ÷ 640 = -0.9296875
-0.9296875 x 100 = -92.97%