-40.03% is the change from 647 to 388
Calculation steps:
[( 388 - 647 ) ÷ 647] x 100 = -40.03%
Formula
Percentage change = [(388 - 647) / 647] x 100
Subtract the new number by the original number
388 - 647 = -259
-259 ÷ 647 = -0.40030911901081917
-0.40030911901081917 x 100 = -40.03%