-21.96% is the change from 642 to 501
Calculation steps:
[( 501 - 642 ) ÷ 642] x 100 = -21.96%
Formula
Percentage change = [(501 - 642) / 642] x 100
Subtract the new number by the original number
501 - 642 = -141
-141 ÷ 642 = -0.21962616822429906
-0.21962616822429906 x 100 = -21.96%