-23.52% is the change from 642 to 491
Calculation steps:
[( 491 - 642 ) ÷ 642] x 100 = -23.52%
Formula
Percentage change = [(491 - 642) / 642] x 100
Subtract the new number by the original number
491 - 642 = -151
-151 ÷ 642 = -0.235202492211838
-0.235202492211838 x 100 = -23.52%