-21.37% is the change from 641 to 504
Calculation steps:
[( 504 - 641 ) ÷ 641] x 100 = -21.37%
Formula
Percentage change = [(504 - 641) / 641] x 100
Subtract the new number by the original number
504 - 641 = -137
-137 ÷ 641 = -0.21372854914196568
-0.21372854914196568 x 100 = -21.37%