-38.66% is the change from 820 to 503
Calculation steps:
[( 503 - 820 ) ÷ 820] x 100 = -38.66%
Formula
Percentage change = [(503 - 820) / 820] x 100
Subtract the new number by the original number
503 - 820 = -317
-317 ÷ 820 = -0.38658536585365855
-0.38658536585365855 x 100 = -38.66%