-4.02% is the change from 671 to 644
Calculation steps:
[( 644 - 671 ) ÷ 671] x 100 = -4.02%
Formula
Percentage change = [(644 - 671) / 671] x 100
Subtract the new number by the original number
644 - 671 = -27
-27 ÷ 671 = -0.040238450074515646
-0.040238450074515646 x 100 = -4.02%