-39.5% is the change from 838 to 507
Calculation steps:
[( 507 - 838 ) ÷ 838] x 100 = -39.5%
Formula
Percentage change = [(507 - 838) / 838] x 100
Subtract the new number by the original number
507 - 838 = -331
-331 ÷ 838 = -0.39498806682577564
-0.39498806682577564 x 100 = -39.5%