-4.76% is the change from 672 to 640
Calculation steps:
[( 640 - 672 ) ÷ 672] x 100 = -4.76%
Formula
Percentage change = [(640 - 672) / 672] x 100
Subtract the new number by the original number
640 - 672 = -32
-32 ÷ 672 = -0.047619047619047616
-0.047619047619047616 x 100 = -4.76%