-31.78% is the change from 645 to 440
Calculation steps:
[( 440 - 645 ) ÷ 645] x 100 = -31.78%
Formula
Percentage change = [(440 - 645) / 645] x 100
Subtract the new number by the original number
440 - 645 = -205
-205 ÷ 645 = -0.3178294573643411
-0.3178294573643411 x 100 = -31.78%