-4.33% is the change from 670 to 641
Calculation steps:
[( 641 - 670 ) ÷ 670] x 100 = -4.33%
Formula
Percentage change = [(641 - 670) / 670] x 100
Subtract the new number by the original number
641 - 670 = -29
-29 ÷ 670 = -0.04328358208955224
-0.04328358208955224 x 100 = -4.33%