-21.98% is the change from 646 to 504
Calculation steps:
[( 504 - 646 ) ÷ 646] x 100 = -21.98%
Formula
Percentage change = [(504 - 646) / 646] x 100
Subtract the new number by the original number
504 - 646 = -142
-142 ÷ 646 = -0.21981424148606812
-0.21981424148606812 x 100 = -21.98%