-4.32% is the change from 671 to 642
Calculation steps:
[( 642 - 671 ) ÷ 671] x 100 = -4.32%
Formula
Percentage change = [(642 - 671) / 671] x 100
Subtract the new number by the original number
642 - 671 = -29
-29 ÷ 671 = -0.043219076005961254
-0.043219076005961254 x 100 = -4.32%