-39.44% is the change from 644 to 390
Calculation steps:
[( 390 - 644 ) ÷ 644] x 100 = -39.44%
Formula
Percentage change = [(390 - 644) / 644] x 100
Subtract the new number by the original number
390 - 644 = -254
-254 ÷ 644 = -0.3944099378881988
-0.3944099378881988 x 100 = -39.44%