-39.9% is the change from 837 to 503
Calculation steps:
[( 503 - 837 ) ÷ 837] x 100 = -39.9%
Formula
Percentage change = [(503 - 837) / 837] x 100
Subtract the new number by the original number
503 - 837 = -334
-334 ÷ 837 = -0.39904420549581837
-0.39904420549581837 x 100 = -39.9%