-21.84% is the change from 641 to 501
Calculation steps:
[( 501 - 641 ) ÷ 641] x 100 = -21.84%
Formula
Percentage change = [(501 - 641) / 641] x 100
Subtract the new number by the original number
501 - 641 = -140
-140 ÷ 641 = -0.21840873634945399
-0.21840873634945399 x 100 = -21.84%