-2.28% is the change from 657 to 642
Calculation steps:
[( 642 - 657 ) ÷ 657] x 100 = -2.28%
Formula
Percentage change = [(642 - 657) / 657] x 100
Subtract the new number by the original number
642 - 657 = -15
-15 ÷ 657 = -0.0228310502283105
-0.0228310502283105 x 100 = -2.28%