-38.73% is the change from 821 to 503
Calculation steps:
[( 503 - 821 ) ÷ 821] x 100 = -38.73%
Formula
Percentage change = [(503 - 821) / 821] x 100
Subtract the new number by the original number
503 - 821 = -318
-318 ÷ 821 = -0.3873325213154689
-0.3873325213154689 x 100 = -38.73%