-39.91% is the change from 644 to 387
Calculation steps:
[( 387 - 644 ) ÷ 644] x 100 = -39.91%
Formula
Percentage change = [(387 - 644) / 644] x 100
Subtract the new number by the original number
387 - 644 = -257
-257 ÷ 644 = -0.39906832298136646
-0.39906832298136646 x 100 = -39.91%