-21.77% is the change from 643 to 503
Calculation steps:
[( 503 - 643 ) ÷ 643] x 100 = -21.77%
Formula
Percentage change = [(503 - 643) / 643] x 100
Subtract the new number by the original number
503 - 643 = -140
-140 ÷ 643 = -0.2177293934681182
-0.2177293934681182 x 100 = -21.77%